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path: root/security/tomoyo/realpath.c
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2016-09-27fs: rename "rename2" i_op to "rename"Miklos Szeredi
Generated patch: sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2` sed -i "s/\brename2\b/rename/g" `git grep -wl rename2` Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-27vfs: remove unused i_op->renameMiklos Szeredi
No in-tree uses remain. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2015-04-15VFS: security/: d_backing_inode() annotationsDavid Howells
most of the ->d_inode uses there refer to the same inode IO would go to, i.e. d_backing_inode() Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11constify tomoyo_realpath_from_path()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-26tomoyo: Fix pathname calculation breakage.Tetsuo Handa
Commit 7177a9c4b509 ("fs: call rename2 if exists") changed "struct inode_operations"->rename == NULL if "struct inode_operations"->rename2 != NULL . TOMOYO needs to check for both ->rename and ->rename2 , or a system on (e.g.) ext4 filesystem won't boot. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
2014-04-01get rid of pointless checks for NULL ->i_opAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03vfs: trim includes a bitAl Viro
[folded fix for missing magic.h from Tetsuo Handa] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03tomoyo: stop including hell knows whatAl Viro
tomoyo/realpath.c needs exactly one include - that of common.h. It pulls everything the thing needs, without doing ridiculous garbage such as trying to include ../../fs/internal.h. If that alone doesn't scream "layering violation", I don't know what does; and these days it's all for nothing, since it fortunately does not use any symbols defined in there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-08TOMOYO: Fix pathname handling of disconnected paths.Tetsuo Handa
Current tomoyo_realpath_from_path() implementation returns strange pathname when calculating pathname of a file which belongs to lazy unmounted tree. Use local pathname rather than strange absolute pathname in that case. Also, this patch fixes a regression by commit 02125a82 "fix apparmor dereferencing potentially freed dentry, sanitize __d_path() API". Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-06fix apparmor dereferencing potentially freed dentry, sanitize __d_path() APIAl Viro
__d_path() API is asking for trouble and in case of apparmor d_namespace_path() getting just that. The root cause is that when __d_path() misses the root it had been told to look for, it stores the location of the most remote ancestor in *root. Without grabbing references. Sure, at the moment of call it had been pinned down by what we have in *path. And if we raced with umount -l, we could have very well stopped at vfsmount/dentry that got freed as soon as prepend_path() dropped vfsmount_lock. It is safe to compare these pointers with pre-existing (and known to be still alive) vfsmount and dentry, as long as all we are asking is "is it the same address?". Dereferencing is not safe and apparmor ended up stepping into that. d_namespace_path() really wants to examine the place where we stopped, even if it's not connected to our namespace. As the result, it looked at ->d_sb->s_magic of a dentry that might've been already freed by that point. All other callers had been careful enough to avoid that, but it's really a bad interface - it invites that kind of trouble. The fix is fairly straightforward, even though it's bigger than I'd like: * prepend_path() root argument becomes const. * __d_path() is never called with NULL/NULL root. It was a kludge to start with. Instead, we have an explicit function - d_absolute_root(). Same as __d_path(), except that it doesn't get root passed and stops where it stops. apparmor and tomoyo are using it. * __d_path() returns NULL on path outside of root. The main caller is show_mountinfo() and that's precisely what we pass root for - to skip those outside chroot jail. Those who don't want that can (and do) use d_path(). * __d_path() root argument becomes const. Everyone agrees, I hope. * apparmor does *NOT* try to use __d_path() or any of its variants when it sees that path->mnt is an internal vfsmount. In that case it's definitely not mounted anywhere and dentry_path() is exactly what we want there. Handling of sysctl()-triggered weirdness is moved to that place. * if apparmor is asked to do pathname relative to chroot jail and __d_path() tells it we it's not in that jail, the sucker just calls d_absolute_path() instead. That's the other remaining caller of __d_path(), BTW. * seq_path_root() does _NOT_ return -ENAMETOOLONG (it's stupid anyway - the normal seq_file logics will take care of growing the buffer and redoing the call of ->show() just fine). However, if it gets path not reachable from root, it returns SEQ_SKIP. The only caller adjusted (i.e. stopped ignoring the return value as it used to do). Reviewed-by: John Johansen <john.johansen@canonical.com> ACKed-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org
2011-09-14TOMOYO: Add socket operation restriction support.Tetsuo Handa
This patch adds support for permission checks for PF_INET/PF_INET6/PF_UNIX socket's bind()/listen()/connect()/send() operations. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2011-07-14TOMOYO: Update kernel-doc.Tetsuo Handa
Update comments for scripts/kernel-doc and fix some of errors reported by scripts/checkpatch.pl . Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2011-06-29TOMOYO: Change pathname for non-rename()able filesystems.Tetsuo Handa
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/ ), 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, this patch changes pathname representations for filesystems which do not support rename() operation (e.g. proc, sysfs, securityfs). Examples: /proc/self/mounts => proc:/self/mounts /sys/kernel/security/ => sys:/kernel/security/ /dev/pts/0 => devpts:/0 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2011-01-07fs: dcache scale d_unhashedNick Piggin
Protect d_unhashed(dentry) condition with d_lock. This means keeping DCACHE_UNHASHED bit in synch with hash manipulations. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-10-25fs: take dcache_lock inside __d_pathChristoph Hellwig
All callers take dcache_lock just around the call to __d_path, so take the lock into it in preparation of getting rid of dcache_lock. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-02TOMOYO: Remove alias keyword.Tetsuo Handa
Some programs behave differently depending on argv[0] passed to execve(). TOMOYO has "alias" keyword in order to allow administrators to define different domains if requested pathname passed to execve() is a symlink. But "alias" keyword is incomplete because this keyword assumes that requested pathname and argv[0] are identical. Thus, remove "alias" keyword (by this patch) and add syntax for checking argv[0] (by future patches). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02TOMOYO: Support longer pathname.Tetsuo Handa
Allow pathnames longer than 4000 bytes. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02TOMOYO: Split files into some pieces.Tetsuo Handa
security/tomoyo/common.c became too large to read. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02TOMOYO: Add interactive enforcing mode.Tetsuo Handa
Since the behavior of the system is restricted by policy, we may need to update policy when you update packages. We need to update policy in the following cases. * The pathname of files has changed. * The dependency of files has changed. * The access permissions required has increased. The ideal way to update policy is to rebuild from the scratch using learning mode. But it is not desirable to change from enforcing mode to other mode if the system has once entered in production state. Suppose MAC could support per-application enforcing mode, the MAC becomes useless if an application that is not running in enforcing mode was cracked. For example, the whole system becomes vulnerable if only HTTP server application is running in learning mode to rebuild policy for the application. So, in TOMOYO Linux, updating policy is done while the system is running in enforcing mode. This patch implements "interactive enforcing mode" which allows administrators to judge whether to accept policy violation in enforcing mode or not. A demo movie is available at http://www.youtube.com/watch?v=b9q1Jo25LPA . Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-05-10TOMOYO: Use stack memory for pending entry.Tetsuo Handa
Use stack memory for pending entry to reduce kmalloc() which will be kfree()d. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-05-06TOMOYO: Use mutex_lock_interruptible.Tetsuo Handa
Some of TOMOYO's functions may sleep after mutex_lock(). If OOM-killer selected a process which is waiting at mutex_lock(), the to-be-killed process can't be killed. Thus, replace mutex_lock() with mutex_lock_interruptible() so that the to-be-killed process can immediately return from TOMOYO's functions. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-05-06Merge branch 'master' into nextJames Morris
2010-05-06TOMOYO: Use GFP_NOFS rather than GFP_KERNEL.Tetsuo Handa
In Ubuntu, security_path_*() hooks are exported to Unionfs. Thus, prepare for being called from inside VFS functions because I'm not sure whether it is safe to use GFP_KERNEL or not. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits) init: Open /dev/console from rootfs mqueue: fix typo "failues" -> "failures" mqueue: only set error codes if they are really necessary mqueue: simplify do_open() error handling mqueue: apply mathematics distributivity on mq_bytes calculation mqueue: remove unneeded info->messages initialization mqueue: fix mq_open() file descriptor leak on user-space processes fix race in d_splice_alias() set S_DEAD on unlink() and non-directory rename() victims vfs: add NOFOLLOW flag to umount(2) get rid of ->mnt_parent in tomoyo/realpath hppfs can use existing proc_mnt, no need for do_kern_mount() in there Mirror MS_KERNMOUNT in ->mnt_flags get rid of useless vfsmount_lock use in put_mnt_ns() Take vfsmount_lock to fs/internal.h get rid of insanity with namespace roots in tomoyo take check for new events in namespace (guts of mounts_poll()) to namespace.c Don't mess with generic_permission() under ->d_lock in hpfs sanitize const/signedness for udf nilfs: sanitize const/signedness in dealing with ->d_name.name ... Fix up fairly trivial (famous last words...) conflicts in drivers/infiniband/core/uverbs_main.c and security/tomoyo/realpath.c
2010-03-03get rid of ->mnt_parent in tomoyo/realpathAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-03get rid of insanity with namespace roots in tomoyoAl Viro
passing *any* namespace root to __d_path() as root is equivalent to just passing it {NULL, NULL}; no need to bother with finding the root of our namespace in there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-02-15TOMOYO: Add garbage collector.Tetsuo Handa
This patch adds garbage collector support to TOMOYO. Elements are protected by "struct srcu_struct tomoyo_ss". Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-02-15TOMOYO: Merge headers.Tetsuo Handa
Gather structures and constants scattered around security/tomoyo/ directory. This is for preparation for adding garbage collector since garbage collector needs to know structures and constants which TOMOYO uses. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-02-15TOMOYO: Add refcounter on string data.Tetsuo Handa
Add refcounter to "struct tomoyo_name_entry" and replace tomoyo_save_name() with tomoyo_get_name()/tomoyo_put_name() pair so that we can kfree() when garbage collector is added. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-01-27TOMOYO: Remove usage counter for temporary memory.Tetsuo Handa
TOMOYO was using own memory usage counter for detecting memory leak. But as kernel 2.6.31 introduced memory leak detection mechanism ( CONFIG_DEBUG_KMEMLEAK ), we no longer need to have own counter. We remove usage counter for memory used for permission checks, but we keep usage counter for memory used for policy so that we can apply quota. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-01-11TOMOYO: Remove memory pool for list elements.Tetsuo Handa
Currently, TOMOYO allocates memory for list elements from memory pool allocated by kmalloc(PAGE_SIZE). But that makes it difficult to kfree() when garbage collector is added. Thus, remove memory pool and use kmalloc(sizeof()). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2010-01-11TOMOYO: Remove memory pool for string data.Tetsuo Handa
Currently, TOMOYO allocates memory for string data from memory pool allocated by kmalloc(PAGE_SIZE). But that makes it difficult to kfree() when garbage collector is added. Thus, remove memory pool and use kmalloc(strlen()). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-12-15TOMOYO: Use RCU primitives for list operationTetsuo Handa
Replace list operation with RCU primitives and replace down_read()/up_read() with srcu_read_lock()/srcu_read_unlock(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-12-09TOMOYO: Compare filesystem by magic number rather than by name.Tetsuo Handa
Please apply below one after merging 1557d33007f63dd96e5d15f33af389378e5f2e54 (Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6). ---------- [PATCH for 2.6.33] TOMOYO: Compare filesystem by magic number rather than by name. We can use magic number for checking whether the filesystem is procfs or not. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6: (43 commits) security/tomoyo: Remove now unnecessary handling of security_sysctl. security/tomoyo: Add a special case to handle accesses through the internal proc mount. sysctl: Drop & in front of every proc_handler. sysctl: Remove CTL_NONE and CTL_UNNUMBERED sysctl: kill dead ctl_handler definitions. sysctl: Remove the last of the generic binary sysctl support sysctl net: Remove unused binary sysctl code sysctl security/tomoyo: Don't look at ctl_name sysctl arm: Remove binary sysctl support sysctl x86: Remove dead binary sysctl support sysctl sh: Remove dead binary sysctl support sysctl powerpc: Remove dead binary sysctl support sysctl ia64: Remove dead binary sysctl support sysctl s390: Remove dead sysctl binary support sysctl frv: Remove dead binary sysctl support sysctl mips/lasat: Remove dead binary sysctl support sysctl drivers: Remove dead binary sysctl support sysctl crypto: Remove dead binary sysctl support sysctl security/keys: Remove dead binary sysctl support sysctl kernel: Remove binary sysctl logic ...
2009-11-20security/tomoyo: Add a special case to handle accesses through the internal ↵Eric W. Biederman
proc mount. With the change of sys_sysctl going through the internal proc mount we no longer need to handle security_sysctl in tomoyo as we have valid pathnames for all sysctl accesses. There is one slight caveat to that in that all of the paths from the internal mount look like "/sys/net/ipv4/ip_local_port_range" instead of "/proc/sys/net/ipv4/ip_local_port_range" so tomoyo needs to add the "/proc" portion manually when resolving to full path names to get what it expects. This change teaches tomoyo perform that modification. Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-10-29tomoyo: improve hash bucket dispersionStephen Hemminger
When examining the network device name hash, it was discovered that the low order bits of full_name_hash() are not very well dispersed across the possible values. When used by filesystem code, this is handled by folding with the function hash_long(). The only other non-filesystem usage of full_name_hash() at this time appears to be in TOMOYO. This patch should fix that. I do not use TOMOYO at this time, so this patch is build tested only. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-06-09TOMOYO: Add description of lists and structures.Tetsuo Handa
This patch adds some descriptions of lists and structures. This patch contains no code changes. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-06-03TOMOYO: Remove redundant markers.Tetsuo Handa
Remove '/***** START/STOP *****/' markers. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-05-09Reduce path_lookup() abusesAl Viro
... use kern_path() where possible [folded a fix from rdd] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-14tomoyo: version bump to 2.2.0.Tetsuo Handa
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-31Get rid of indirect include of fs_struct.hAl Viro
Don't pull it in sched.h; very few files actually need it and those can include directly. sched.h itself only needs forward declaration of struct fs_struct; Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-02-23TOMOYO: Do not call tomoyo_realpath_init unless registered.Tetsuo Handa
tomoyo_realpath_init() is unconditionally called by security_initcall(). But nobody will use realpath related functions if TOMOYO is not registered. So, let tomoyo_init() call tomoyo_realpath_init(). This patch saves 4KB of memory allocation if TOMOYO is not registered. Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12Memory and pathname management functions.Kentaro Takeda
TOMOYO Linux performs pathname based access control. To remove factors that make pathname based access control difficult (e.g. symbolic links, "..", "//" etc.), TOMOYO Linux derives realpath of requested pathname from "struct dentry" and "struct vfsmount". The maximum length of string data is limited to 4000 including trailing '\0'. Since TOMOYO Linux uses '\ooo' style representation for non ASCII printable characters, maybe TOMOYO Linux should be able to support 16336 (which means (NAME_MAX * (PATH_MAX / (NAME_MAX + 1)) * 4 + (PATH_MAX / (NAME_MAX + 1))) including trailing '\0'), but I think 4000 is enough for practical use. TOMOYO uses only 0x21 - 0x7E (as printable characters) and 0x20 (as word delimiter) and 0x0A (as line delimiter). 0x01 - 0x20 and 0x80 - 0xFF is handled in \ooo style representation. The reason to use \ooo is to guarantee that "%s" won't damage logs. Userland program can request open("/tmp/file granted.\nAccess /tmp/file ", O_WRONLY | O_CREAT, 0600) and logging such crazy pathname using "Access %s denied.\n" format will cause "fabrication of logs" like Access /tmp/file granted. Access /tmp/file denied. TOMOYO converts such characters to \ooo so that the logs will become Access /tmp/file\040granted.\012Access\040/tmp/file denied. and the administrator can read the logs safely using /bin/cat . Likewise, a crazy request like open("/tmp/\x01\x02\x03\x04\x05\x06\x07\x08\x09", O_WRONLY | O_CREAT, 0600) will be processed safely by converting to Access /tmp/\001\002\003\004\005\006\007\010\011 denied. Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>