--- trunk/ccs-patch/README.ccs 2007/05/21 11:55:33 229 +++ trunk/1.8.x/ccs-patch/README.ccs 2011/03/15 05:23:03 4724 @@ -1,7 +1,7 @@ Notes for TOMOYO Linux project This is a handy Mandatory Access Control patch for Linux kernels. -This patch is released under the GPL. +This patch is released under the GPLv2. Project URL: http://tomoyo.sourceforge.jp/ @@ -16,10 +16,6 @@ This project was very inspired by the comic "Card Captor SAKURA", one of the CLAMP's masterworks. -The names SAKURA and TOMOYO and SYAORAN were borrowed from the comic -with the heartfelt thanks to CLAMP. - - ChangeLog: @@ -197,7 +193,7 @@ @ Fix handling of trailing '\*' in PathMatchesToPattern(). PathMatchesToPattern("/tmp/", "/tmp/\*") returned true - because "\*" matches to "more than or equals to 0 character + because "\*" matches "zero or more repetitions of characters until '/' or end". But since this is a comparison between directory and non-directory, this should not match. @@ -408,14 +404,14 @@ @ Change behavior of pathname pattern matching. - Until now, it was impossible to use patterns like "\*.txt" - because "\*" matched to more than 0 characters until next '/'. - Now, "\*" matches to more than 0 characters. + Until now, it was impossible to use patterns like "\*.txt" because + "\*" matched zero or more repetitions of characters until next '/'. + Now, "\*" matches zero or more repetitions of characters. Until now, it was impossible to use patterns like "\$00" - because "\$" matched to more than 1 digits until next + because "\$" matched one or more repetitions of digits until next non digit character. - Now, "\$" matches to more than 1 digits. + Now, "\$" matches one or more repetitions of digits. Also, new patterns "\x" "\X" "\a" "\A" "\@" are added. @@ -432,7 +428,7 @@ @ Change matching rule for CheckFileACL(). - Until now, only first entry that matched to the requested pathname + Until now, only first entry that matched the requested pathname was used for permission checking. For example, two entries "2 /tmp/file-\$.txt" @@ -448,7 +444,7 @@ This may potentially cause trouble because the result of permission checks depends on the order of entries. - Now, all entries that matched to the requested pathname + Now, all entries that matched the requested pathname are used for permission checking so that the result of permission checks doesn't depend on the order of entries. @@ -475,7 +471,7 @@ succeeds to invoke do_execve() with filename = "/bin/ls" and argv[0] = "/bin/cat". - I introduced a keyword that permits the mismatch of + I introduced a directive that permits the mismatch of basename of filename and argv[0]. Fix 2006/08/10 @@ -489,14 +485,14 @@ domain ACL. For example, "1 /bin/sh if task.euid!=0" - + allows the domain to execute /bin/sh only when the process's euid is not 0, and "6 /home/\*/\* if task.uid=path1.uid" allows the domain to read-write user's home directory - only when the file's owner matches to the process's uid. + only when the file's owner matches the process's uid. Fix 2006/08/22 @@ -762,14 +758,14 @@ if /some/program is called from "some_domain" domain. "some_domain" can be just the last component of domainname. - For example, giving "/bin/mail" as "some_domain" matches to + For example, giving "/bin/mail" as "some_domain" matches all domains whose domainname ends with "/bin/mail". Fix 2007/01/19 @ Allow reuse of memory allocated for domain policy. - As with domain policy, unlike other policies, didn't have + Regarding domain policy, unlike other policies, didn't have "is_deleted" flag and new memory were allocated if the deleted entries are given again. But to allow administrators switch domain policy periodically, @@ -875,7 +871,7 @@ based on realpath while argv[0] check is done based on the symlink's pathname and argv[0], this specification will allow attackers behave as /bin/cat in the domain of /bin/ls if "/bin/ls and /bin/cat are - links to /sbin/busybox" and "the attacker is permitted to create + links to /sbin/busybox" and "the attacker is permitted to create a symlink named ~/cat that points to /bin/ls" and "the attacker is permitted to run /bin/ls". So, I changed to compare the basename of realpath and argv[0]. @@ -914,4 +910,1894 @@ Don't try "A\-B\+C" because "\+" is not addition operator. -Version 1.4.1 2007/??/?? Minor update release. +Fix 2007/05/24 + + @ Fix autobind hook. + + The location to call SAKURA_MayAutobind() in net/ipv4/udp.c + and net/ipv6/udp.c were wrong. + +Fix 2007/06/03 + + @ Add a space in MakeMountOptions(). + + I forgot to add a space after "atime" and "noatime". + +Version 1.4.1 2007/06/05 Minor update release. + +Fix 2007/07/04 + + @ Fix ReadAddressGroupPolicy() bug. + + ReadAddressGroupPolicy() fails if both "path_group" and "address_group" + are used because I forgot to set "head->read_var1 = NULL". + +Fix 2007/07/10 + + @ Add compat_sys_stime() hook. + + Some of 64bit kernels support compat_sys_stime() + but permission check was missing. + +Version 1.4.2 2007/07/13 Bug fix release. + +Fix 2007/08/06 + + @ Remove mount-flags manipulation. + + Until now, administrator is permitted to turn on/off specific mount + options regardless of mount options passed to kernel. + I removed this feature because "exact option matching" sounds better than + "automatic option enabler/disabler". + + @ Remove /proc/ccs/info/mapping . + + I removed /proc/ccs/info/mapping because nobody seems to use this + feature. + + @ Call external policy loader automatically. + + Until now, users had to add init=/.init parameter to load policy + before /sbin/init starts. + I inserted call_usermodehelper() to call external policy loader when + execve("/sbin/init") is requested and external policy loader exists. + + This change will remove init=/.init parameter from most environment, + although call_usermodehelper() can't handle interactive operations. + + @ Move external policy loader from /.init to /sbin/ccs-init . + + Installing programs in / directory is not good for packaging. + +Fix 2007/08/13 + + @ Update external policy loader. + + It turned out that /sbin/ccs-init invoked via call_usermodehelper() + can handle interactive operations by opening /dev/console . + Now, there is no difference between init=/sbin/ccs-init and + call_usermodehelper("/sbin/ccs-init"), and users no longer need to + add init=/sbin/ccs-init parameter to load policy before /sbin/init + starts. + +Fix 2007/08/14 + + @ Update recvmsg() hooks. + + Until now, it was impossible to apply network access control for + incoming UDP and RAW packets if they are brought to userland using + read() or recvmsg() with NULL address because address buffer is NULL. + I moved hooks from sock_recvmsg() to skb_recv_datagram() so that + network access control for incoming UDP and RAW packets always work. + +Fix 2007/08/16 + + @ Return appropriate error code for CheckMountPermission(). + + I was returning -EPERM if something is wrong with CheckMountPermission(). + But SELinux determines whether selinuxfs is supported by kernel + based on whether error code is -ENODEV or not. + So I stopped returning -EPERM unconditionally. + +Fix 2007/08/17 + + @ Remove initializer directive. + + Use "initialize_domain" instead of "initializer". + +Fix 2007/08/21 + + @ Fix "allow_argv0 ... if if ..." bug. + + It was impossible to use a word "if" to the second argument of + allow_argv0 if condition part is used. + +Fix 2007/08/24 + + @ Move /proc/ccs/\*/\* to /proc/ccs/\* . + + Some pathnames for /proc/ccs/ interface were changed. + +Fix 2007/09/05 + + @ Drop MSG_PEEK'ed message before skb_free_datagram(). + + I need to remove head message from unwanted source + from socket's receive queue so that the caller can pick up + next message from wanted source with MSG_PEEK flags. + +Version 1.5.0 2007/09/20 Usability enhancement release. + +Fix 2007/09/27 + + @ Avoid eating memory after quota exceeded. + + Although ACL entries in a domain won't be added if the domain's quota + has exceeded, SaveName() in AddFileACL() is called anyway. + This caused unneeded memory consumption. + + Now, quota checking is done before getting domain_acl_lock lock. + This may exceed quota by one or two entries, but that won't matter. + +Fix 2007/10/16 + + @ Add environment variable check. + + There are environment variables that may cause dangerous behavior + like LD_\* . + So I introduced 'allow_env' directive that allows specified + environment variable inherited to next domain. + Unlike other permissions, this check is done at execve() time + using next domain's ACL information. + + To manage commonly inherited environments like PATH , + you can use 'allow_env' directive in exception policy + to globally grant specified environment variable. + +Fix 2007/11/05 + + @ Replace semaphore with mutex. + + I replaced semaphore with mutex. + + @ Add missing down() in AddReservedEntry(). + + Mutex debugging capability told me that I had forgotten to call down() + since TOMOYO version 1.3.2 . + This function is not called by learning mode, + so the semaphore's counter will not overflow for normal usage. + +Fix 2005/11/27 + + @ Fix ReadTable() truncation bug. + + "snprintf(str, size, format, ...) >= size" means truncated. + But I was checking for "snprintf(str, size, format, ...) > size". + As a result, some entries might be dumped without '\n'. + + @ Purge direct "->prev"/"->next" manipulation. + + All list manipulations use "struct list_head" or "struct list1_head". + "struct list1_head" doesn't have "->prev" member to save memory usage. + +Fix 2007/11/29 + + @ Add missing semaphore in GetEXE(). + + mm->mmap_sem was missing. + +Fix 2007/12/17 + + @ Remove unused EXPORT_SYMBOL(). + + Mark some functions static. + +Fix 2007/12/18 + + @ Fix AddMountACL() rejection bug. + + To my surprise, "mount --bind source dest" accepts + not only "both source and dest are directory" + but also "both source and dest are non-directory". + I was rejecting if dest is not a directory in AddMountACL(). + + @ Change log format. + + Profile number and mode is added in audit logs. + +Fix 2008/01/03 + + @ Change directive for file's read/write/execute permission. + + Directives for file's read/write/execute permissions were + 4/2/1 respectively. But for easier understanding, they are now + replaced by read/write/execute (e.g. "allow_read" instead of "4"). + But for easier inputting, 4/2/1 are still accepted instead of + allow_read/allow_write/allow_execute respectively. + + @ Change internal data structure. + + Since I don't have more than 16 types of file permissions, + I combined them using bit-fields. + + Each entry had a field for conditional permission support. + But since this field is unlikely used, I separated the field from + common part. + + These changes will reduce memory used by policy. + +Fix 2008/01/15 + + @ Add ptrace() hook. + + To prevent attackers from controlling important processes using + ptrace(), I added a hook for ptrace(). + Most programs (except strace(1) and gdb(1)) won't use ptrace(2). + + @ Fix sleep condition check in CheckSocketRecvDatagramPermission(). + + It seems that correct method to use is in_atomic() + rather than in_interrupt() because in_atomic() returns nonzero + whenever scheduling is not allowed. + +Fix 2008/02/05 + + @ Use find_task_by_vpid() instead of find_task_by_pid(). + + Kernel 2.6.24 introduced PID namespace. + To search PID given from userland, the kernel needs to use + find_task_by_vpid() instead of find_task_by_pid(). + +Fix 2008/02/14 + + @ Add execve() parameter checking. + + Until now, it was impossible to check argv[] and envp[] parameters + passed to execve(). + I expanded conditional permission syntax so that + { argc, envc, argv[] , envp[] } parameters can be checked if needed. + This will allow administrator permit execution of /bin/sh only when + /bin/sh is invoked in the form of "/bin/sh -c" and environment variable + HOME is set by specifying + + allow_execute /bin/sh if exec.argv[1]="-c" exec.envp["HOME"]!=NULL + + in the policy. + This extension will make exploit codes difficult to start /bin/sh because + they unlikely set up environment variables and unlikely specify "-c" + option when invoking /bin/sh , whereas proper functions likely set up + environment variables and likely specify "-c" option. + +Fix 2008/02/18 + + @ Add process state checking. + + Until now, it was impossible to change ACL without executing program. + I added three variables for performing stateful checking within a domain. + You can set current process's state like: + + allow_network TCP accept @TRUSTED_HOSTS 1024-65535 ; set task.state[0]=1 + allow_network TCP accept @UNTRUSTED_HOSTS 1024-65535 ; set task.state[0]=0 + + and you can use the state like + + allow_read /path/to/important/file if task.state[0]=1 + + in the policy. + The state changes when the request was granted by the MAC's policy, + so please be careful with situations where the state has changed + successfully but the request was not processed because of other reasons + (e.g. out of memory). + +Fix 2008/02/26 + + @ Support /proc/ccs/ access by non-root user. + + Until now, only root user can access /proc/ccs/ interface. + But to permit /proc/ccs/ access by non-root user so that it won't require + ssh login by root user when administrating from remote host, + I made "(current->uid == 0 && current->euid == 0)" requirement optional. + If this requirement is disabled, only "conventional DAC permission + checks" and "/proc/ccs/manager checks" are used. + +Fix 2008/02/29 + + @ Add sleep_on_violation feature. + + Some exploit codes (e.g. trans2open for Samba) continue running + until it achieves the purpose of the exploit code (e.g. invoke /bin/sh). + + If such code is injected due to buffer overflow but the kernel + rejects the request, it triggers infinite "Permission denied" loop. + As a result, the CPU usage becomes 100% and gives bad effects to + the rest of processes. + This is a side effect of rejecting the request from the exploit code + which wouldn't happen if the request from the exploit code was granted. + + To avoid such CPU consumption, I added a penalty that forcibly + sleeps for specified period when a request is rejected. + + This penalty doesn't work if the exploit code does nothing but + continue running, but I think most exploit code's purpose is + to start some program rather than to slow down the target system. + + @ Add alt_exec feature. + + Since TOMOYO Linux's approach is "know all essential requests in advance + and create policy that permits only them", you can regard anomalous + requests as attacks (if you want to do so). + + Common MAC implementations merely reject requests that violate policy. + But I added a special handler for execve() to TOMOYO Linux. + + This handler is triggered when a process requested to execute a program + but the request was rejected by the policy. + This handler executes a program specified by the administrator + instead of a program requested by the process. + + Most attackers attempt to execute /bin/sh to start something malicious. + Attackers execute an exploit code using buffer overflow vulnerability + to steal control of a process. But this handler can get back control + if an exploit code requests execve() that is not permitted by policy. + + By default, this handler does nothing (i.e. merely reject execve() + request). You can specify any program to start what you want to do. + + You can redirect attackers to somewhere else (e.g. honey pot). + This makes it possible to act your Linux box as an on-demand honey pot + while keeping regular services for your usage. + + You can collect information of the attacker (e.g. IP address) and + update firewall configuration. + + You can silently terminate a process who requested execve() + that is not permitted by policy. + +Fix 2008/03/03 + + @ Add "force_alt_exec" directive. + + To be able to fully utilize "alt_exec" feature, + I added "force_alt_exec" directive so that + all execute requests are replaced by the execute request of a program + specified by alt_exec feature. + + If this directive is specified for a domain, the domain no longer + executes any programs regardless of the mode of file access control + (i.e. the domain won't execute even if MAC_FOR_FILE=0 ). + Instead, the domain executes the program specified by alt_exec feature + and the program specified by alt_exec feature validates the execute + request and executes it if it is appropriate to execute. + + If you can tolerate that there is no chance to return an error code + to the caller to tell the execute request was rejected, + this is more flexible approach than in-kernel execve() parameter + checking because we can do argv[] and envp[] checking easily. + +Fix 2008/03/04 + + @ Use string for access control mode. + + An integer expression for access control mode sometimes confuses + administrators because profile number is also an integer expression. + To avoid confusion between profile number and access control mode, + I introduced a string expression for access control mode. + + Modes which take an integer between 0 and 3. + + 0 -> disabled + 1 -> learning + 2 -> permissive + 3 -> enforcing + + Modes which take 0 or 1. + + 0 -> disabled + 1 -> enabled + +Fix 2008/03/10 + + @ Rename "force_alt_exec" directive to "execute_handler". + + To be able to use different programs for validating execve() parameters, + I moved the location to specify the program's pathname from profile + to domain policy. + + The "execute_handler" directive takes one pathname which is + invoked whenever execve() request is issued. Thus, any "allow_execute" + directives in a domain with "execute_handler" are ignored. + This directive is designed for validating expected/desirable execve() + requests in userspace, although there is no way to tell the caller + that the execve() request was rejected. + + @ Rename "alt_exec" directive to "denied_execute_handler". + + The "denied_execute_handler" directive takes one pathname which is + invoked only when execve() request was rejected. In other words, + this program is invoked only when the following conditions are met. + + (1) None of "allow_execute" directives in the domain matched. + (2) The execve() request was rejected in enforcing mode. + (3) "execute_handler" directive is not used by the domain. + + This directive is designed for handling unexpected/undesirable execve() + requests, to redirect the process issuing such requests to somewhere. + +Fix 2008/03/18 + + @ Fix wrong/redundant locks in pre-vfs functions. + + lock_kernel()/unlock_kernel() in pre_vfs_rename() were redundant for + 2.6 kernels. + + Locking order in pre_vfs_link() and pre_vfs_unlink() for 2.4 kernels + after 2.4.33 were different from before 2.4.32 . + +Fix 2008/03/28 + + @ Disable execute handler loop. + + To be able to use "execute_handler" in a "keep_domain" domain, + ignore "execute_handler" and "denied_execute_handler" directives + if the current process is executing programs specified by + "execute_handler" or "denied_execute_handler" directive. + + This exception is needed to avoid infinite execute handler loop. + If a domain has both "keep_domain" and "execute_handler", + any execute request by that domain is handled by an execute handler, + and the execute handler attempts to process original execute request. + But the original execute request is handled by the same execute handler + unless the execute handler ignores "execute_handler". + + @ Update coding style. + + I rewrote the code to pass scripts/checkpatch.pl as much as possible. + Function names were changed to use only lower letters. + +Version 1.6.0 2008/04/01 Feature enhancement release. + +Fix 2008/04/14 + + @ Fix "Compilation failures" and "Initialization ordering bugs" + with kernels before 2.4.30/2.6.11 . + + 2.6 kernels before 2.6.9 didn't have include/linux/hardirq.h , + resulting compilation error at #include . + I added #elif condition. + + CentOS 4.6's 2.6.9 kernel calls do_execve() before initialization of + ccs_alloc(), resulting NULL pointer dereference. + I changed __initcall to core_initcall. + + CentOS 4.6's 2.6.9 kernel backported kzalloc() from 2.6.14 , + resulting compilation error at kzalloc(). + I modified prototype of kzalloc(). + +Fix 2008/04/20 + + @ Fix "Compilation failures" with kernels before 2.4.30/2.6.11 . + + Turbolinux 10 Server's 2.6.8 kernel backported kzalloc() as an inlined + function, resulting compilation error at kzalloc(). + I converted kzalloc() from an inlined function into a macro. + +Fix 2008/04/21 + + @ Add workaround for gcc 3.2.2's inline bug. + + RedHat Linux 9's gcc 3.2.2 generated a bad code + if ((var_of_u8 & 0x000000BF) & 0x80000000) { } + where the expected code is + if ((var_of_u8 & 0xBF) & 0x80) { } + when embedding ccs_acl_type2() into print_entry(), + resulting runtime BUG(). + I added the expected code explicitly as a workaround. + +Fix 2008/05/06 + + @ Add memory quota. + + 1.5.x returns -ENOMEM when FindNextDomain() failed to create a new + domain, but I forgot to return -ENOMEM when find_next_domain() failed to + create a new domain. + + A domain is automatically created by find_next_domain() only if + the domain for the requested program doesn't exist. + This behavior is for the administrator's convenience. + The administrator needn't to know how many domains are needed for running + the whole programs in the system beforehand when developing the policy. + But the administrator does not want the kernel to reject execution of the + requested program when developing the policy. + + So, I think it is better to grant execution of programs even if + find_next_domain() failed to create a new domain than reject execution. + Thus, I decided not to return -ENOMEM when find_next_domain() failed to + create a new domain. This exception breaks the domain transition rules, + so I print "transition_failed" warning in /proc/ccs/domain_policy + when this exception happened. + + Also, to prevent the system from being halted by unexpectedly allocating + all kernel memory for the policy, I added memory quota. + This quota is configurable via /proc/ccs/meminfo like + + echo Shared: 1048576 > /proc/ccs/meminfo + echo Private: 1048576 > /proc/ccs/meminfo + +Version 1.6.1 2008/05/10 Bug fix release. + +Fix 2008/06/04 + + @ Check open mode of /proc/ccs/ interface. + + It turned out that I can avoid allocating memory for reading if + FMODE_READ is not set and memory for writing if FMODE_WRITE is not set. + + @ Wait for completion of /sbin/ccs-init . + + Since 2.4 kernel's call_usermodehelper() can't wait for termination of + the executed program, I was using the close() request of + /proc/ccs/meminfo to indicate that loading policy has finished. + But since /proc/ccs/meminfo could be accessed for setting memory quota + by /etc/ccs/ccs-post-init , I stopped using the close() request. + The policy loader no longer need to access /proc/ccs/meminfo to notify + the kernel that loading policy has finished. + +Fix 2008/06/05 + + @ Fix realpath for pipes and sockets. + + Kernel 2.6.22 and later use different method for calculating d_path(). + Since fs/realpath.c didn't notice the change, the realpath of pipes + appeared as "pipe:" rather than "pipe:[\$]" when they are opened via + /proc/PID/fd/ directory. + + @ Add process's information into /proc/ccs/query . + + While /proc/ccs/grant_log and /proc/ccs/reject_log contain process's + information, /proc/ccs/query doesn't contain it. + To be able to utilize ccs-queryd and ccs-notifyd more, I added it into + /proc/ccs/query . + +Fix 2008/06/10 + + @ Allow using patterns for globally readable files. + + To allow users specify locale specific files to globally readable files, + I relaxed checking in update_globally_readable_entry(). + +Fix 2008/06/11 + + @ Remove ALLOW_ENFORCE_GRACE parameter. + + Since unexpected requests caused by doing software updates can happen + in all profiles, users likely have to write ALLOW_ENFORCE_GRACE=enabled + to all profiles. And it makes meaningless to allow users to selectively + enable specific profile's ALLOW_ENFORCE_GRACE parameter. + So, I removed ALLOW_ENFORCE_GRACE parameter. + Now, the system behaves as if ALLOW_ENFORCE_GRACE=enabled is specified. + The behavior of "delayed enforcing" mode is defined in the following + order. + + (1) The requests are rejected immediately if nobody is opening + /proc/ccs/query interface. + (2) The requests will be rejected in 10 seconds if somebody other than + ccs-queryd (such as less(1)) is opening /proc/ccs/query interface, + for such process doesn't write dummy decisions. + +Fix 2008/06/22 + + @ Pass escaped pathname to audit_execute_handler_log(). + + I was passing unescaped pathname to audit_execute_handler_log() + which causes /proc/ccs/grant_log contain whitespace characters + if execute handler's pathname contains whitespace characters. + +Fix 2008/06/25 + + @ Return 0 when ccs_may_umount() succeeds. + + I forgot to clear error value in ccs_may_umount() when the requested + directory didn't match "deny_unmount" directive. As a result, any umount() + request with RESTRICT_UNMOUNT=enforcing returned -EPERM error. + +Version 1.6.2 2008/06/25 Usability enhancement release. + +Fix 2008/07/01 + + @ Fix "Compilation failure" with 2.4.20 kernel. + + RedHat Linux 9's 2.4.20 kernel backported O(1) scheduler patch, + resulting compilation error at ccs_load_policy(). + I added defined(TASK_DEAD) check. + +Fix 2008/07/08 + + @ Don't check permissions if vfsmount is NULL. + + Some filesystems (e.g. unionfs) pass NULL vfsmount. + I changed fs/tomoyo_file.c not to try to calculate pathnames + if vfsmount is NULL. + +Version 1.6.3 2008/07/15 Bug fix release. + +Fix 2008/08/21 + + @ Add workaround for gcc 4.3's bug. + + In some environments, fs/tomoyo_network.c could not be compiled + because of gcc 4.3's bug. + I modified save_ipv6_address() to use "integer literal" value + instead for "static const u8" variable. + + @ Change prototypes of some functions. + + To support 2.6.27 kernels, I replaced "struct nameidata" with + "struct path" for some functions. + + @ Detect distributor specific patches automatically. + + Since kernels with AppArmor patch applied is increasing, + I introduced a mechanism which determines whether specific patches + are applied or not, based on "#define" directives in the patches. + +Fix 2008/08/29 + + @ Remove "-ccs" suffix from Makefile's EXTRAVERSION. + + To reduce conflicts on Makefile's EXTRAVERSION, + I removed "-ccs" suffix from ccs-patch-2.\*.diff . + Those who build kernels without using specs/build-\*.sh , + please edit EXTRAVERSION tag manually so that original kernels + will not be overwritten by TOMOYO Linux kernels. + +Version 1.6.4 2008/09/03 Minor update release. + +Fix 2008/09/09 + + @ Add "try again" response to "delayed enforcing" mode. + + To be able to handle pathname changes caused by software updates, + "delayed enforcing" mode was introduced. It allows administrator to + grant access requests which are about to be rejected by the kernel. + + To be able to handle pathname changes caused by software updates better, + I introduced "try again" response. As "delayed enforcing" mode sleeps + a process which violated policy, administrator can update policy while + the process is sleeping. This "try again" response allows administrator + to restart policy checks from the beginning after updating policy. + +Fix 2008/09/11 + + @ Remember whether the process is allowed to write to /proc/ccs/ interface. + + Since programs for manipulating policy (e.g. ccs-queryd ) are installed + in the form of RPM/DEB packages, these programs lose the original + pathnames when they are updated by the package manager. The package + manager renames these programs before deleting these programs so that + the package manager can rollback the operation. + This causes a problem when the programs are listed into /proc/ccs/manager + using pathnames, as the programs will no longer be allowed to write to + /proc/ccs/ interface while the process of old version of the program is + alive. + + To solve this problem, I modified to remember the fact that the process + is once allowed to write to /proc/ccs/ interface until the process + attempts to execute a different program. + This change makes it impossible to revoke permission to write to + /proc/ccs/ interface without killing the process, but it will be better + than nonfunctioning ccs-queryd program. + +Fix 2008/09/19 + + @ Allow selecting a domain by PID. + + Sometimes we want to know what ACLs are given to specific PID, but + finding a domainname for that PID from /proc/ccs/.process_status and + reading ACLs from /proc/ccs/domain_policy by the domainname is very slow. + Thus, I modified /proc/ccs/domain_policy to allow selecting a domain by + PID. For example, to read domain ACL of current process from bash, + run as follows. + + # exec 100<>/proc/ccs/domain_policy + # echo select pid=$$ >&100 + # while read -u 100; do echo $REPLY; done + + If a domain is once selected by PID, reading /proc/ccs/domain_policy will + print only that domain if that PID exists or print nothing otherwise. + + @ Disallow concurrent /proc/ccs/ access using the same file descriptor. + + Until now, one process can read() from /proc/ccs/ while other process + that shares the file descriptor can write() to /proc/ccs/ . + But to implement "Allow selecting a domain by PID" feature, I disabled + concurrent read()/write() because the feature need to modify read buffer + while writing. + +Fix 2008/10/01 + + @ Add retry counter into /proc/ccs/query . + + To be able to handle some of queries from /proc/ccs/query without user's + interaction, I added retry counter for avoiding infinite loop caused by + "try again" response. + +Fix 2008/10/07 + + @ Don't transit to new domain until do_execve() succeeds. + + Until now, a process's domain was updated to new domain which the process + will belong to before do_execve() succeeds so that the kernel can do + permission checks for interpreters and environment variables based on + new domain. But this caused a subtle problem when other process sends + signals to the process, for the process returns to old domain if + do_execve() failed. + + So, I modified to pass new domain to functions so that I can avoid + modifying a process's domain before do_execve() succeeds. + + @ Use old task state for audit logs. + + Until now, audit logs were generated using the task state after + processing "; set task.state" part. But to generate accurate logs, + I modified to save the task state before processing "; set task.state" + part and use the saved state for audit logs. + + @ Use a structure for passing parameters. + + As the number of parameters is increasing, I modified to use a structure + for passing parameters. + +Fix 2008/10/11 + + @ Remove domain_acl_lock mutex. + + I noticed that I don't need to keep all functions that modify an ACL of + a domain mutually exclusive. Since each functions handles different type + of ACL, locking is needed only when they append an ACL to a domain. + So, I modified to use local locks. + +Fix 2008/10/14 + + @ Fix ccs_check_condition() bug. + + Due to a bug in ccs_check_condition(), it was impossible to use + task.state[0] task.state[1] task.state[2] inside condition part + if the ACL does not treat a pathname. For example, an ACL like + + allow_network TCP connect @HTTP_SERVERS 80 if task.state[0]=100 + + didn't work. + +Fix 2008/10/15 + + @ Show process information in /proc/ccs/.process_status . + + To be able to determine a process's type, I added a command "info PID" + which returns process information of the specified PID in + "PID manager=\* execute_handler=\* state[0]=\$ state[1]=\$ state[2]=\$" + format. + +Fix 2008/10/20 + + @ Use rcu_dereference() when walking the list. + + I was using "dependency ordering" for appending an element to a list + without asking the reader to take a lock. But "dependency ordering" + is not respected by DEC Alpha or by some aggressive value-speculation + compiler optimizations. + + On such environment, use of "dependency ordering" can lead to system + crash because the reader might read uninitialized value of newly + appended element. + + To prevent the reader from reading uninitialized value of newly appended + element, I inserted rcu_dereference() when walking the list. + +Fix 2008/11/04 + + @ Use sys_getpid() instead for current->pid. + + Kernel 2.6.24 introduced PID namespace. + + To compare PID given from userland, I can't use current->pid. + So, I modified to use sys_getpid() instead for current->pid. + + I modified to use task_tgid_nr_ns() for 2.6.25 and later instead for + current->tgid when checking /proc/self/ in get_absolute_path(). + +Fix 2008/11/07 + + @ Fix is_alphabet_char(). + + is_alphabet_char() should match 'A' - 'Z' and 'a' - 'z', + but was matching from 'A' - 'F' and 'a' - 'f'. + + @ Add /proc/ccs/.execute_handler . + + Process information became visible to userspace by + "Show process information in /proc/ccs/.process_status" feature. + However, programs specified by execute_handler directive may run as + non root user, making it impossible to see process information. + + So, I added a new interface that allows execute handler processes + to see process information. The content of /proc/ccs/.execute_handler is + identical to /proc/ccs/.process_status . + +Version 1.6.5 2008/11/11 Third anniversary release. + +Fix 2008/12/01 + + @ Introduce "task.type=execute_handler" condition. + + The execute_handler directive is very very powerful. You can use this + directive to do anything you want to do (e.g. logging and validating and + modifying command line parameters and environment variables, opening and + closing and redirecting files, creating pipes to implement antivirus and + spam filtering, deploying a DMZ between the ssh daemon and the login + shells). + + To be able to use this directive in a domain with keep_domain directive + while limiting access to resources needed for such purposes to only + programs invoked as an execute handler process, I added a new condition. + + In learning mode, "if task.type=execute_handler" condition part will be + automatically added for requests issued by an execute_handler process. + + @ Introduce file's type and permissions as conditions. + + To be able to limit file types a process can access, I added + new conditions for checking file's type and permissions. + For example, + + allow_read /etc/fstab if path1.type=file path1.perm=0644 + + will allow opening /etc/fstab for reading only if /etc/fstab is a regular + file and it's permission is 0644, and + + allow_write /dev/null if path1.type=char path1.dev_major=1 path1.dev_minor=3 + + will allow opening /dev/null for writing only if /dev/null is a character + device file with major=1 and minor=3 attributes. + + @ Add memory quota for temporary memory used for auditing. + + Although there are MAX_GRANT_LOG and MAX_REJECT_LOG parameters + which limit the number of entries for audit logs so that we can avoid + memory consumption by audit logs, it would be more convenient if we can + also limit the size in bytes. + Thus, I added a new quota line. + + echo Dynamic: 1048576 > /proc/ccs/meminfo + + This quota is not applied to temporary memory used for permission checks. + +Fix 2008/12/09 + + @ Fix ccs_can_save_audit_log() checks. + + Due to incorrect statement "if (ccs_can_save_audit_log() < 0)" + while ccs_can_save_audit_log() is boolean, MAX_GRANT_LOG and + MAX_REJECT_LOG were not working. + + This bug will trigger OOM killer if /usr/sbin/ccs-auditd is not working. + +Fix 2008/12/24 + + @ Add "ccs_" prefix. + + To be able to tell whether a symbol is TOMOYO Linux related or not, + I added "ccs_" prefix as much as possible. + + @ Fix ccs_check_flags() error message. + + I meant to print SYAORAN-ERROR: message when error == -EPERM, + but I was printing it when error == 0 since 1.6.0 . + +Fix 2009/01/05 + + @ Use kmap_atomic()/kunmap_atomic() for reading "struct linux_binprm". + + As remove_arg_zero() uses kmap_atomic(KM_USER0), I modified to use + kmap_atomic(KM_USER0) rather than kmap(). + +Fix 2009/01/28 + + @ Fix "allow_read" + "allow_write" != "allow_read/write" problem. + + Since 1.6.0 , due to a bug in ccs_update_single_path_acl(), + appending "allow_read/write" entry didn't update internal "allow_read" + and "allow_write" entries. As a result, attempt to open(O_RDWR) succeeds + but open(O_RDONLY) and open(O_WRONLY) fail. + + Workaround is to write an entry twice when newly appending that entry. + If written twice, internal "allow_read" and "allow_write" entries + are updated. + +Fix 2009/02/26 + + @ Fix profile read error. + + Incorrect profiles were shown in /proc/ccs/profile + if either CONFIG_SAKURA or CONFIG_TOMOYO is disabled. + +Fix 2009/03/02 + + @ Undelete CONFIG_TOMOYO_AUDIT option. + + While HDD-less systems can use profiles with MAX_GRANT_LOG=0 and + MAX_REJECT_LOG=0 , I undeleted CONFIG_TOMOYO_AUDIT option for saving + memory used for /proc/ccs/grant_log and /proc/ccs/reject_log interfaces. + +Fix 2009/03/13 + + @ Show only profile entry names ever specified. + + Even if an administrator specifies only COMMENT= and MAC_FOR_FILE= + entries for /proc/ccs/profile , all available profile entries are shown. + This was designed to help administrators to know what entries are + available, but sometimes makes administrators feel noisy because of + entries showing default values. + + Thus, I modified to show only profile entry names ever specified. + +Fix 2009/03/18 + + @ Add MAC_FOR_IOCTL functionality. + + To be able to restrict ioctl() requests, I added MAC_FOR_IOCTL + functionality. + + This functionality requires modification of ccs-patch-\*.diff . + + @ Use better name for socket's pathname. + + Until now, socket's pathname was represented as "socket:[\$]" format + where \$ is inode's number. But inode's number is useless for name based + access control. Therefore, I modified to represent socket's pathname as + "socket:[family=\$:type=\$:protocol=\$]" format. + + This will help administrator to control ioctl() against sockets more + precisely. + + @ Fix misplaced ccs_capable() call. (only 2.6.8-\* and 2.6.9-\*) + + Location to insert ccs_capable(TOMOYO_SYS_IOCTL) in sys_ioctl() was + wrong since version 1.1 . + + @ Insert ccs_check_ioctl_permission() call. + + To make MAC_FOR_IOCTL functionality working, I inserted + ccs_check_ioctl_permission() call into ccs-patch-\*.diff . + +Fix 2009/03/23 + + @ Move sysctl()'s check from ccs-patch-\*.diff to fs/tomoyo_file.c . + + Since try_parse_table() in kernel/sysctl.c is almost identical between + all versions, I moved that function to fs/tomoyo_file.c . + + @ Relocate definitions and functions. + + To reduce exposed symbols, I relocated some definitions and functions. + +Fix 2009/03/24 + + @ Add CONFIG_TOMOYO_BUILTIN_INITIALIZERS option. + + Some systems don't have /sbin/modprobe and /sbin/hotplug . + Thus, I made these pathnames configurable. + +Version 1.6.7 2009/04/01 Feature enhancement release. + +Fix 2009/04/06 + + @ Drop "undelete domain" command. + + I added "undelete domain" command on 2007/01/19, but never used by policy + management tools. The garbage collector I added on 2007/01/29 will + automatically reuse memory and allow administrators switch domain policy + periodically, provided that the administrator kills processes in old + domains before recreating new domains with the same domainnames. + + Thus, I dropped "undelete domain" command. + + @ Escape invalid characters in ccs_check_mount_permission2(). + + ccs_check_mount_permission2() was passing unencoded strings to printk() + and ccs_update_mount_acl() and ccs_check_supervisor(). This may cause + /proc/ccs/system_policy and /proc/ccs/query to contain invalid + characters within a string. + +Fix 2009/04/07 + + @ Fix IPv4's "address_group" handling error. + + Since 1.6.5 , due to lack of ntohl() (byte order conversion) in + ccs_update_address_group_entry(), "address_group" with IPv4 address was + not working. + + This problem happens on little endian platforms (e.g. x86). + +Fix 2009/05/08 + + @ Add condition for symlink's target pathname. + + Until now, "allow_symlink" keyword allows creation of a symlink but does + not check the symlink's target. Usually it is no problem because + permission checks are done using dereferenced pathname. But in some + cases, we should restrict the symlink's target. For example, + "ln -s .htpasswd /var/www/html/readme.html" by CGI program should be + blocked because we will allow Apache to read both + /var/www/html/readme.html and /var/www/html/.htpasswd . + + Thus, I added new condition, "symlink.target". + + allow_symlink /var/www/html/\*.html if symlink.target="\*.html" + + allow_symlink /var/www/html/\*\-.\* if symlink.target="\*\-.\*" + + @ Don't return -EAGAIN at ccs_socket_recvmsg_permission(). + + It turned out that it is not permitted for accept() and recvmsg() to + return -EAGAIN if poll() said connections/datagrams are ready. However, + recvmsg() may return -EAGAIN and potentially confuse some applications + because ccs_socket_recvmsg_permission() is returning -EAGAIN. + + Thus, I modified ccs_socket_recvmsg_permission() to return -ENOMEM + rather than -EAGAIN. + +Fix 2009/05/19 + + @ Don't call get_fs_type() with a mutex held. + + Until now, when ccs_update_mount_acl() is called with unsupported + filesystem, /sbin/modprobe is executed from get_fs_type() to load + filesystem module. And get_fs_type() does not return until /sbin/modprobe + finishes. + + This means that it will cause deadlock if /sbin/modprobe (which is + executed via get_fs_type() in ccs_update_mount_acl()) calls + ccs_update_mount_acl(); although it won't happen unless an administrator + inserts execute_handler to call mount() requests in learning mode or to + add "allow_mount" entries to /proc/ccs/system_policy . + + I modified to unlock the mutex before calling get_fs_type(). + +Fix 2009/05/20 + + @ Update recvmsg() hooks. + + Since 1.5.0, I was doing network access control for incoming UDP and RAW + packets inside skb_recv_datagram(). But to synchronize with LSM version, + I moved ccs_recv_datagram_permission() hook from skb_recv_datagram() to + udp_recvmsg()/udpv6_recvmsg()/raw_recvmsg()/rawv6_recvmsg() with name + change to ccs_recvmsg_permission(). + +Version 1.6.8 2009/05/28 Feature enhancement release. + +Fix 2009/07/03 + + @ Fix buffer overrun when used with CONFIG_SLOB=y . + + Since 1.6.7 , ccs_allocate_execve_entry() was requesting for only 4000 + bytes while the comment says it is 4096 bytes. This may lead to buffer + overrun when slob allocator is used, for slob allocator allocates exactly + 4000 bytes whereas slab and slub allocators allocate 4096 bytes. + +Fix 2009/09/01 + + @ Add garbage collector support. + + Until now, it was impossible to release memory used by deleted policy. + I added SRCU based garbage collector so that memory used by deleted + policy will be automatically released. + + @ Remove word length limitation and line length limitation. + + Until now, the max length of a word is 4000 and the max length of a line + is 8192. To be able to handle longer pathnames, I removed these + limitations. Now, the max length (except the domainname and + argv[]/envp[]) is 128K (which is the max amount of memory kmalloc() + can allocate in most environments). + + @ Support more fine grained profile configuration. + + Profile was reconstructed. + + @ Support more fine grained parameters restrictions. + + "allow_create", "allow_mkdir", "allow_mkfifo", "allow_mksock" check + create mode. "allow_mkblock" and "allow_mkchar" check create mode and + major/minor device numbers. "allow_chmod" check new mode. "allow_chown" + checks new owner. "allow_chgrp" checks new group. + + @ Allow number grouping. + + To help specifying numeric values, a new directive "number_group" is + introduced. + + @ Remove "alias" directive and "allow_argv0" directive. + + Until now, "allow_execute" used dereferenced pathname if it is a symlink + unless explicitly specified by "alias" directive. + + Now, "allow_execute" uses symlink's pathname if it is a symlink. + "exec.realpath" in "if" clause checks the dereferenced pathname. + "exec.argv[0]" in "if" clause checks the invocation name. + + @ Remove /proc/ccs/system_policy and /etc/ccs/system_policy.conf . + + "deny_autobind" was moved to /proc/ccs/exception_policy and + /etc/ccs/exception_policy.conf . Other directives were moved to + /proc/ccs/domain_policy and /etc/ccs/domain_policy.conf . + + @ Remove syaoran filesystem. + + Since "allow_create"/"allow_mkdir"/"allow_mkfifo"/"allow_mksock"/ + "allow_mkblock"/"allow_mkchar"/"allow_chmod"/"allow_chown"/"allow_chgrp" + can restrict mode changes and owner/group changes, there is no need to + restrict these changes at filesystem level. + + Thus, I removed syaoran filesystem. + + @ Reduce spinlocks. + + Until now, TOMOYO was using own list for detecting memory leak. But as + kernel 2.6.31 introduced memory leak detection mechanism + ( CONFIG_DEBUG_KMEMLEAK ), TOMOYO no longer needs to use own list. + + I removed the list to reduce use of spinlocks. + + @ Rewrite ccs-patch-2.\*.diff . + + ccs-patch-2.\*.diff was rewritten like LSM hooks. + + @ Don't check "allow_read/write" for open-for-ioctl-only. + + open(pathname, 3) means open for ioctl() only. + Until now, TOMOYO was checking "allow_read/write" for open(pathname, 3). + But since TOMOYO checks "allow_ioctl" for ioctl(), I modified not to + require "allow_read/write" for open(pathname, 3). + + @ Add missing sigqueue() and tgsigqueue() hooks. + + Until now, kill(), tkill(), tgkill() had hooks but sigqueue() and + tgsigqueue() didn't. + + @ Move files from fs/ to security/ccsecurity. + + Config menu section changed from "File systems" to "Security options". + + Kernel config symbols changed from CONFIG_SAKURA CONFIG_TOMOYO + CONFIG_SYAORAN to CONFIG_CCSECURITY . + + @ Add global PID to audit logs. + + ccs-queryd was using domainname for reaching the domain which the process + belongs to, but the domain could be deleted while ccs-queryd is handling + policy violation. If the domain is deleted, ccs-queryd no longer can + reach the domain by domainname. Thus, ccs-queryd now uses PID for + reaching the domain which the process belongs to. + + Kernel 2.6.24 introduced PID namespace. The PID in access logs generated + by a process inside a container is useless for ccs-queryd for reaching + the domain which the process belongs to. + + Thus, I added global PID in audit logs. + + @ Transit to new domain before do_execve() succeeds. + + Permission checks for interpreters and environment variables are + done using new domain. In order to allow ccs-queryd to reach the new + domain via global PID, I reverted "Don't transit to new domain until + do_execve() succeeds." made on 2008/10/07. + +Version 1.7.0 2009/09/03 Feature enhancement release. + +Fix 2009/09/04 + + @ Fix wrong ccs_profile() calls. + + I can't call ccs_profile() for profile existence test because + ccs_profile() never returns NULL. + +Fix 2009/09/06 + + @ Fix wrong error code in ccs_try_alt_exec(). + + ccs_try_alt_exec() was returning ENOMEM when kmalloc() failed. + It needs to return -ENOMEM to fail. + +Fix 2009/09/10 + + @ Do not check umount() permission for mount(MS_MOVE) requests. + + Until 1.6.x , umount() restriction was black listing. In 1.7.0 , it is + white listing. This change caused "mount --move old new" requests to + require "allow_unmount old" permission in addition to + "allow_mount old new --move 0" permission. + But we don't want to allow umount(old) requests when we want to allow + only mount(old, new, MS_MOVE) requests. Thus, I modified not to check + "allow_unmount old" permission for mount(old, new, MS_MOVE) requests. + +Fix 2009/09/11 + + @ Support recursive match operators. + + Until now, ccs_path_matches_pattern() did not support recursive + comparison. Thus, users had to repeat "/\*" when they want to specify + recursively. + + I introduced "\{" and "\}" as repetition operator. + To ensure consistency with TOMOYO's '/'-tokenized pattern matching rules + and "\-" operator, only "/\{dir\}/" sequences (where dir does not contain + '/') is permitted. + +Fix 2009/09/24 + + @ Don't check chmod/chown capability for requests from kernel. + + Until now, ccs_setattr_permission() was inserted in notify_change(). + But notify_change() is also called by requests from kernel (e.g. UnionFS) + and it made difficult to use TOMOYO on UnionFS. + + Thus, I moved ccs_capable() checks from ccs_setattr_permission() to + ccs_chmod_permission() and ccs_chown_permission(), and removed + ccs_setattr_permission(). + +Fix 2009/09/25 + + @ Embed more information into audit logs. + + Until now, /proc/ccs/grant_log /proc/ccs/reject_log /proc/ccs/query were + not printing file's information (e.g. file's uid/gid/mode). + + Recently, users who started using "if" clause expect that the learning + mode automatically adds various conditions like "if task.uid=path1.uid". + + But the profile will become too complicated if I support all possible + conditions. Thus, I added all information which is enough to generate + "if" clause with all possible conditions from audit logs. + + Now, the learning mode got different usage. Users can specify + "CONFIG::learning={ max_entry=0 }" in the profile. All requests which + are not permitted by policy will be sent to /proc/ccs/reject_log with + "mode=learning" header lines. Users can selectively append conditions + and append to the policy using "/usr/sbin/ccs-loadpolicy -d". + The learning mode with "CONFIG::learning={ max_entry=0 }" is almost + the same with the permissive mode, only difference is "mode=learning" + and "mode=permissive". + +Fix 2009/10/05 + + @ Fix size truncation bug at ccs_memcmp(). + + ccs_memcmp() was using "u8" for size parameter by error. Therefore, when + size >= 256 was passed to ccs_memcmp(), it was doing partial comparison + (incorrect result) or read overrun (CPU stall). + + ccs_memcmp() should use "size_t" for size parameter because size of + "struct ccs_condition" may exceed 256 bytes if complicated condition was + given. + +Fix 2009/10/08 + + @ Add CONFIG_CCSECURITY_DEFAULT_LOADER option. + + I made the default policy loader's pathname ( /sbin/ccs-init ) + configurable. + + @ Add CONFIG_CCSECURITY_ALTERNATIVE_TRIGGER option. + + Some environments do not have /sbin/init . In such environments, we need + to use different program's pathname (e.g. /init or /linuxrc ) as + activation trigger. + + Thus, I made the alternative trigger ( /sbin/ccs-start ) configurable. + +Fix 2009/11/02 + + @ Fix buffer contention. + + A permission like + + allow_env PATH if exec.envp["PATH"]="/" + + was not working since I was using the same buffer for both environment + variable's name and value. + +Fix 2009/11/03 + + @ Fix memory leak in ccs_write_address_group_policy(). + + I forgot to call kfree() if same entry was added. + + @ Reduce mutexes. + + I was using mutex_lock()/mutex_unlock() so that I can use + atomic_dec_and_test() for removing an element from a list. + I moved that operation to garbage collector in order to reduce frequency + of mutex_lock()/mutex_unlock() calls. + + @ Escape from nested loops correctly. + + In ccs_read_address_group_policy(), I was escaping from nested loops + correctly. But in ccs_read_path_group_policy() and + ccs_read_number_group_policy(), I wasn't. + + As a result, reading path_group and number_group caused kernel oops + when they were not read atomically. + +Fix 2009/11/06 + + @ Fix incorrect allow_mount audit log. + + Audit log for allow_mount was using decimal format. + It needs to use hexadecimal format. + +Fix 2009/11/09 + + @ Add profile version check. + + To avoid upgrading from TOMOYO 1.6.x to TOMOYO 1.7.x without upgrading + /proc/ccs/profile (which results in not protecting the system at all), + I added a check for PROFILE_VERSION= . + +Version 1.7.1 2009/11/11 Fourth anniversary release. + +Fix 2009/11/13 + + @ Don't use core_initcall() for initializing lock for GC. + + Some kernels call TOMOYO's hooks before processing core_initcall(). + Thus, I can't use core_initcall() for initializing lock for GC. + +Fix 2009/11/18 + + @ Don't check "allow_write" permission for open(O_RDONLY | O_TRUNC). + + Since TOMOYO checks "allow_truncate" permission rather than "allow_write" + permission for O_TRUNC, I need to distinguish open(O_RDONLY | O_TRUNC) + and open(O_RDWR | O_TRUNC). But I made a mistake between TOMOYO 1.7.0 and + 1.7.1 which made it impossible for TOMOYO for kernels 2.6.14 and earlier + to distinguish them. + +Fix 2009/11/27 + + @ Use newly created domain's name for domain creation audit log. + + Since 1.7.0 , /proc/ccs/reject_log was by error using existing domain's + name when auditing newly created domain's "use_profile" line. + +Fix 2009/12/12 + + @ Use rcu_read_lock() for find_task_by_pid(). + + Since kernel 2.6.18 , caller of find_task_by_pid() needs to call + rcu_read_lock() rather than read_lock(&tasklist_lock) because find_pid() + uses RCU primitives but spinlock does not prevent RCU callback if + preemptive RCU ( CONFIG_PREEMPT_RCU or CONFIG_TREE_PREEMPT_RCU ) is + enabled. + +Fix 2009/12/15 + + @ Allow deleting "quota_exceeded" and "transition_failed" entries. + + To notify users of "this domain has too many entries to hold" and "some + process in this domain was not able to perform domain transition", + "quota_exceeded" and "transition_failed" messages are used respectively. + These messages were not deletable. But it is more convenient for users + to be notified again if such events occurred again after tuning policy. + Thus, I made these messages deletable. + +Fix 2009/12/17 + + @ Don't check read permission in ccs_try_alt_exec(). + + While I was trying to remove ccs_execve_list list for GC optimization + between TOMOYO 1.7.0 and 1.7.1 , I made a mistake which made TOMOYO to + check allow_read permission of the programs specified by execute_handler + and denied_execute_handler keywords. + + @ Don't check DAC permission if disabled mode. + + I was checking DAC permissions regarding directory entry modification + operations (e.g. mkdir()) even if mode=disabled . It is a waste of CPU + resource to check DAC permissions when MAC permissions are not checked. + Thus, I modified to skip DAC permission checks if mode=disabled . + +Fix 2009/12/19 + + @ Fix memory leak in ccs_environ(). + + When I fixed a bug that a permission like + + allow_env PATH if exec.envp["PATH"]="/" + + was not working (2009/11/02), I allocated two buffers but only one buffer + was released. + + This bug will trigger OOM killer if environment variable checking is + enabled. + +Fix 2010/01/17 + + @ Use current domain's name for execute_handler audit log. + + Since 1.6.7 , /proc/ccs/grant_log was by error using next domain's name + when auditing current domain's "execute_handler" line. + +Fix 2010/03/02 + + @ Allow domain transition without execve(). + + To be able to split permissions for Apache's CGI programs which are + executed without execve(), I added special domain transition which is + performed by atomically writing '\0'-terminated binary string to + /proc/ccs/.transition interface. For example, a process which belongs to + " /usr/sbin/httpd" domain will transit to + " /usr/sbin/httpd //app=cgi1\040id=10000" domain by atomically + writing "app=cgi1 id=10000" + '\0' to /proc/ccs/.transition using + Apache's ap_hook_handler() functionality. + + Note that '\0'-terminated binary string is converted to TOMOYO's string + inside kernel and prefix "//" is automatically added to the string so + that domainname does not conflict with domainnames created by execve(). + Without this prefix, if " /usr/sbin/sshd /bin/bash" domain is + allowed to open /proc/ccs/.transition for writing and + " /usr/sbin/sshd /bin/bash /usr/bin/passwd" domain is allowed to + access /etc/shadow , /bin/bash will be able to access /etc/shadow by + atomically writing "/usr/bin/passwd" + '\0' to /proc/ccs/.transition . + Allowing /bin/bash to access /etc/shadow is not what people want. + + Permission for this operation is checked by "allow_transit" keyword. + Unlike "allow_execute" keyword, the string parameter for "allow_transit" + keyword does not refer a real file on filesystem's namespace. Therefore, + you can store any combination of parameters like LDAP's DN entry in the + string parameter for "allow_transit" keyword. + +Fix 2010/03/08 + + @ Allow building as loadable kernel module. + + To be able to minimize filesize increment of vmlinux, I made it + possible to compile TOMOYO Linux as loadable kernel module. + Although patching the kernel source and recompiling the kernel are + inevitable, this change will make it easier to enable TOMOYO Linux + when there is a filesize limitation on vmlinux (e.g. embedded systems). + +Fix 2010/03/25 + + @ Fix ccs_get_ipv6_address() bug. + + Since 1.7.0 , ccs_get_ipv6_address() was by error returning address of + "struct list_head ccs_address_list" if memory allocation failed. + As a result, ccs_put_ipv6_address() will modify memory near + "struct list_head ccs_address_list" if memory allocation failed. + +Fix 2010/03/26 + + @ Fix ccs_lport_reserved() bug. + + Since 1.7.0 , ccs_lport_reserved() was by error checking wrong port + number. As a result, "deny_autobind" keyword was not working as expected. + +Version 1.7.2 2010/04/01 Feature enhancement release. + +Fix 2010/04/10 + + @ Fix invalid "struct nameidata" to "struct path" conversion macro. + + Regarding kernels 2.6.24 and earlier, I was converting "struct nameidata" + to "struct path" in caller side so that I can unify the callee function's + parameter type. But it turned out that the macro I used did not follow C + standards and did not work with gcc 4.x . As a result, "allow_pivot_root" + keyword was not working as expected. + +Fix 2010/05/05 + + @ Fix incorrect audit on/off control. + + The grant_log= and reject_log= parameters of CONFIG::misc::env were not + used because I forgot to update request type. As a result, those of + CONFIG::file::execute were used for CONFIG::misc::env . + + Those of CONFIG::file::rewrite were not used because I forgot to update + request type. As a result, those of CONFIG::file::truncate were used for + CONFIG::file::rewrite . + +Fix 2010/05/10 + + @ Fix incorrect out of memory warning. + + Out of memory warnings were not printed in some cases by error. + +Fix 2010/05/27 + + @ Add missing rcu_dereference() for ccs_find_execute_handler(). + + Since 1.7.0 , ccs_find_execute_handler() was by error using + list_for_each_entry() rather than list_for_each_entry_rcu(). + This bug affects only Alpha architecture. + +Fix 2010/06/03 + + @ Fix missing sanity check for "file_pattern". + + Since 1.7.0 , ccs_write_pattern_policy() was by error accepting + invalid pathname. + +Fix 2010/06/09 + + @ Add missing ccs_put_name() in ccs_parse_envp(). + + Since 1.7.0 , ccs_parse_envp() was not calling ccs_put_name() if + environment variable's value ('if exec.envp["name"]="value"' condition) + was invalid. + + @ Add missing NULL check in ccs_condition(). + + Since 1.7.0 , if 'if symlink.target=' part was given against non-file + permissions (e.g. allow_env PATH if symlink.target="/"), it triggered + NULL pointer dereference. + +Fix 2010/10/28 + + @ Fix umount() pathname calculation. + + "mount --bind /path/to/file1 /path/to/file2" is legal. + Therefore, "umount /path/to/file2" is also legal. + Do not automatically append trailing '/' if pathname to be unmounted + does not end with '/'. + + @ Add preserve KABI compatibility option. (2.6 kernels only) + + TOMOYO needs "struct ccs_domain_info *" and "u32" for each + "struct task_struct". But embedding these variables into + "struct task_struct" breaks KABI for prebuilt kernel modules (which + means that you will need to rebuild prebuilt kernel modules). + + Since KABI is commonly used (compared to 5 years ago), asking users to + rebuild kernel modules which are not included in kernel package is no + longer preferable. Therefore, I added a new option that keeps + "struct task_struct" unmodified in order to keep KABI. + + Note that you have to use ccs-patch-2.6.\*.diff which patches + kernel/fork.c in order to use this option. Otherwise, TOMOYO will leak + memory whenever "struct task_struct" is released. + + @ Change directives. + + I removed "allow_" prefix from directives. New directives for files are + prefixed with "file ". For example, "allow_read" changed to "file read", + "allow_ioctl" changed to "file ioctl". New directive for "allow_network + TCP" is "network inet stream", "allow_network UDP" is "network inet + dgram", "allow_network RAW" is "network inet raw". New directive for + "allow_env" is "misc env". New directive for "allow_signal" is "ipc + signal". New directive for "allow_capability" is "capability". These new + directives correspond with keywords used by profile's CONFIG lines. + + I removed "deny_rewrite" and "allow_rewrite" directives and introduced + "file append" directive. Thus, permission for open(O_WRONLY | O_APPEND) + changed from "allow_write" + "allow_rewrite" to "file append". + + I removed "SYS_MOUNT", "SYS_UMOUNT", "SYS_CHROOT", "SYS_KILL", + "SYS_LINK", "SYS_SYMLINK", "SYS_RENAME", "SYS_UNLINK", "SYS_CHMOD", + "SYS_CHOWN", "SYS_IOCTL", "SYS_PIVOT_ROOT" keywords from capabilities + because these permissions can be checked by other directives (e.g. + "file mount", "ipc signal"). + + I also removed "conceal_mount" keyword from capabilities because this + check requires hooks in filesystem part while almost all hooks for + filesystem part have moved to LSM by Linux 2.6.34. + + New directive for "execute_handler" is "task auto_execute_handler", + "denied_execute_handler" is "task denied_execute_handler". + + @ Distinguish send() and recv() operations. + + Until now, it was impossible for UDP and IP sockets to allow either + only sending or only receiving because permissions were aggregated with + "connect" keyword. I broke "connect" keyword into "send" and "recv" + keywords so that you can keep access control for send() operation enabled + when you have to disable access control for recv() operation due to + application breakage by discarding incoming datagram. + + @ Add Unix domain socket restriction support. + + Until now, it was possible to restrict only inet domain sockets (i.e. + TCP/UDP/RAW). I added restriction for Unix domain sockets (i.e. stream/ + dgram/seqpacket). New directive "network unix" is added as well as + "network inet" directive. + + @ Allow specifying multiple permissions in a line. + + Until now, only "allow_read/write" can be specified for combination of + "allow_read" + "allow_write". Now, you can combine other permissions as + long as type of parameters for these permissions is same. For example, + "file read/write/append/execute/unlink/truncate /tmp/file" is correct + but "file read/write/create /tmp/file" is wrong because "file create" + requires create mode whereas "file read" and "file write" do not. + + @ Allow wildcard for execute permission and domainname. + + Until now, to execute programs with temporary names, "aggregator" is + needed. To simplify code, I modified to accept wildcards for execute + permission and domainname. Now, you can directly specify + "file execute /tmp/logrotate.\?\?\?\?\?\?" and use + "/tmp/logrotate.\?\?\?\?\?\?" within domainnames. + + @ Change pathname for non-rename()able filesystems. + + LSM version of TOMOYO wants to use /proc/self/ rather than /proc/$PID/ if + $PID matches current thread's process ID in order to prevent current + thread from accessing other process's information unless needed. + But since procfs can be mounted on various locations (e.g. /proc/ /proc2/ + /p/ /tmp/foo/100/p/ ), LSM version of TOMOYO cannot tell that whether the + numeric part in the string returned by __d_path() represents process ID + or not. + + Therefore, to be able to convert from $PID to self no matter where procfs + is mounted, I changed pathname representations for filesystems which do + not support rename() operation (e.g. proc, sysfs, securityfs). + + Now, "/proc/self/mounts" changed to "proc:/self/mounts" and + "/sys/kernel/security/" changed to "sys:/kernel/security/" and + "/dev/pts/0" changed to "devpts:/0". + + @ Add a new keyword "any" for domain transition control. + + To be able to make it easier to apply auto_execute_handler on each + domain, I added "any" keyword to domain transition control keywords. Now, + "initialize_domain /usr/sbin/sshd" changed to + "initialize_domain /usr/sbin/sshd from any" and + "keep_domain /usr/sbin/sshd /bin/bash" changed to + "keep_domain any from /usr/sbin/sshd /bin/bash". + + "keep_domain /path/to/auto_execute_handler from any" will allow you to + apply auto_execute_handler for any domains without creating domains for + auto_execute_handler. + + @ Change buffering mode for reading policy. + + To be able to read() very very long lines correctly, I changed the way + TOMOYO buffers policy for reading. + + @ Introduce "acl_group" keyword. + + Until now, it was possible to specify only "allow_read" and "allow_env" + keywords in the exception policy. + + Since some operations like "file read/write/append /dev/null" and + "network UDP send/recv @DNS_SERVER 53" are very common and should be + permitted to all domains, I introduced "acl_group" keyword for giving + such permissions. + + For example, specify "acl_group 0 file read/write/append /dev/null" in + the exception policy and specify "use_group 0" from the domains in the + domain policy. + + "ignore_global_allow_read" and "ignore_global_allow_env" directives were + removed from domain policy and "use_group" keyword was added. + + @ Remove "if" and "; set" keyword. + + I removed need for specifying these keyword. + You can simply specify like below. + + file read /etc/shadow task.uid=0 + + @ Remove "file_pattern" keyword. + + I removed "file_pattern" keyword because it is impossible to predefine + all possible pathname patterns. Also, learning pathnames using incomplete + patterns makes it difficult to later replace using "path_group" keyword. + + @ Replace verbose= parameter with statistic interface. + + Since it is noisy if a lot of policy violation messages are printed, + I removed printk(). To be able to check whether policy violation occurred + or not, I introduced /proc/ccs/stat interface which counts number of + policy violations occurred. You can firstly check /proc/ccs/stat and then + check /proc/ccs/reject_log . + + @ Remove global preference. + + I removed global preference in order to make code simpler. + + @ Allow controlling generation of access granted logs for per an entry + basis. + + I added per-entry flag which controls generation of grant logs because + Xen and KVM issues ioctl requests so frequently. For example, + + file ioctl /dev/null 0x5401 grant_log=no + + will suppress /proc/ccs/grant_log even if preference says grant_log=yes . + + file ioctl /dev/null 0x5401 grant_log=yes + + will generate /proc/ccs/grant_log even if preference says grant_log=no . + + file ioctl /dev/null 0x5401 + + will generate /proc/ccs/grant_log only if preference says grant_log=yes . + + This flag is intended for frequently accessed resources like + + file read /var/www/html/\{\*\}/\*.html grant_log=no + + . + + @ Automatically create domain by execve() even if enforcing mode. + + Until now, new domains are not created if the domain was not defined and + current domain is enforcing mode ("CONFIG::file::execute=enforcing"). + + To be able to restrict shell session without using "keep_domain", + I changed to create new domains automatically even if current domain is + enforcing mode. + + @ Replace "task.state" with "auto_domain_transition". + + task.state is difficult to use. Thus, I replaced task.state with + auto_domain_transition which performs domain transition instead of + changing current process's state variables. + + If domain transition failed, current process will be killed by SIGKILL + signal. This should not happen in normal circumstances, for you know the + domain to transit to and thereby you will define the domain beforehand + when you use "auto_domain_transition" keyword. + + @ Replace "allow_transit" with "task manual_domain_transition". + + I changed this directive to specify absolute domainname (e.g. + " /usr/sbin/httpd //app=cgi1\040id=10000") rather than virtual + pathname (e.g. "//app=cgi1\040id=10000") because you know the domain to + transit to and thereby you will define the domain beforehand when you use + "task manual_domain_transition" directive. + + This change allows you to jump to arbitrary domain. + + Note that this change also reverts "Change /proc/ccs/info/self_domain ." + made on 2006/10/24. Now, 'cat < /proc/ccs/info/self_domain' will act like + 'cat /proc/ccs/info/self_domain'. Programs depending on old assumption + need to be updated. + + @ Add "task auto_domain_transition". + + This is similar to "task manual_domain_transition", but is automatically + applied whenever conditions are met. For example, + + task auto_domain_transition //./non-root task.uid!=0 + + will automatically jump to " //./non-root" domain if current + process's UID is not 0 whereas + + task manual_domain_transition //./non-root task.uid!=0 + + will jump to " //./non-root" domain if current process's UID is + not 0 and current process wrote " //./non-root" to + /proc/ccs/self_domain interface. + + If domain transition failed, current process will be killed by SIGKILL + signal. + + @ Optimize for object's size. + + I merged similar code in order to reduce object's filesize. + +Version 1.8.0 2010/11/11 Fifth anniversary release. + +Fix 2010/12/01 + + @ Use same interface for audit logs. + + To be able to perform fine grained filtering by /usr/sbin/ccs-auditd , + I merged /proc/ccs/grant_log and /proc/ccs/reject_log as + /proc/ccs/audit and added granted=yes or granted=no to audit logs. + +Fix 2010/12/17 + + @ Split ccs_null_security into ccs_default_security and ccs_oom_security. + + ccs_null_security is used by preserve KABI compatibility option and is + used for providing default values against threads which have not yet + allocated memory for their security contexts. + + If current thread failed to allocate memory for current thread's security + context, current thread uses ccs_null_security. Since current thread is + allowed to modify current thread's security context, current thread might + modify ccs_null_security which should not be modified for any reason. + + Therefore, I split ccs_null_security into ccs_default_security and + ccs_oom_security and use ccs_oom_security when current thread failed to + allocate memory for current thread's security context. + + Threads which do not share ccs_oom_security are not affected by threads + which share ccs_oom_security. Threads which share ccs_oom_security will + experience temporary inconsistency, but such threads are about to be + killed by SIGKILL signal. + +Fix 2011/01/11 + + @ Use filesystem name for unnamed devices when vfsmount is missing. + + "Change pathname for non-rename()able filesystems." changed to use + "$fsname:" if the filesystem does not support rename() operation and + "dev($major,$minor):" otherwise when vfsmount is missing. But it turned + out that it is useless to use "dev($major,$minor):" for unnamed devices + (filesystems with $major == 0). Thus, I changed to use "$fsname:" rather + than "dev($major,$minor):" for filesystems with $major == 0 when vfsmount + is missing. + +Fix 2011/02/07 + + @ Fix infinite loop bug when reading /proc/ccs/audit or /proc/ccs/query . + + In ccs_flush(), head->r.w[0] holds pointer to string data to be printed. + But head->r.w[0] was updated only when the string data was partially + printed (because head->r.w[0] will be updated by head->r.w[1] later if + completely printed). However, regarding /proc/ccs/audit and + /proc/ccs/query , an additional '\0' is printed after the string data was + completely printed. But if free space for read buffer became 0 before + printing the additional '\0', ccs_flush() was returning without updating + head->r.w[0]. As a result, ccs_flush() forever reprints already printed + string data. + +Fix 2011/03/01 + + @ Run garbage collector without waiting for /proc/ccs/ users. + + Currently TOMOYO holds SRCU lock upon open() and releases it upon close() + because list elements stored in the "struct ccs_io_buffer" instances are + accessed until close() is called. However, such SRCU usage causes lockdep + to complain about leaving the kernel with SRCU lock held. Therefore, + I changed to hold/release SRCU upon each read()/write() by selectively + deferring kfree() by keeping track of the "struct ccs_io_buffer" + instances. + +Fix 2011/03/05 + + @ Support built-in policy configuration. + + To be able to start using enforcing mode from the early stage of boot + sequence, I added support for built-in policy configuration and + activating access control without calling external policy loader program. + + This will be useful for systems where operations which can lead to the + hijacking of the boot sequence are needed before loading the policy. + For example, you can activate immediately after loading the fixed part of + policy which will allow only operations needed for mounting a partition + which contains the variant part of policy and verifying (e.g. running GPG + check) and loading the variant part of policy. Since you can start using + enforcing mode from the beginning, you can reduce the possibility of + hijacking the boot sequence. + +Fix 2011/03/10 + + @ Remove /proc/ccs/meminfo interface. + + Please use /proc/ccs/stat interface instead. + +Fix 2011/03/15 + + @ Pack policy when printing via /proc/ccs/ interface. + + The kernel side is ready for accepting packed input like + + file read/write/execute /path/to/file + + but was using unpacked output like + + file read /path/to/file + file write /path/to/file + file execute /path/to/file + + because most of userland tools were not ready for accepting packed input. + + The advantages of using packed policy are that it makes policy files + smaller and it speeds up loading/saving policy files. + + Since most of userland tools are ready for accepting packed input by now, + I changed to use packed policy for both input and output.