user/sven/linux.git/kernel/auditsc.c, branch v4.1.37

audit: fix a double fetch in audit_log_single_execve_arg()

2016-08-20T03:07:58Z

[ Upstream commit 43761473c254b45883a64441dd0bc85a42f3645c ] There is a double fetch problem in audit_log_single_execve_arg() where we first check the execve(2) argumnets for any "bad" characters which would require hex encoding and then re-fetch the arguments for logging in the audit record[1]. Of course this leaves a window of opportunity for an unsavory application to munge with the data. This patch reworks things by only fetching the argument data once[2] into a buffer where it is scanned and logged into the audit records(s). In addition to fixing the double fetch, this patch improves on the original code in a few other ways: better handling of large arguments which require encoding, stricter record length checking, and some performance improvements (completely unverified, but we got rid of some strlen() calls, that's got to be a good thing). As part of the development of this patch, I've also created a basic regression test for the audit-testsuite, the test can be tracked on GitHub at the following link: * https://github.com/linux-audit/audit-testsuite/issues/25 [1] If you pay careful attention, there is actually a triple fetch problem due to a strnlen_user() call at the top of the function. [2] This is a tiny white lie, we do make a call to strnlen_user() prior to fetching the argument data. I don't like it, but due to the way the audit record is structured we really have no choice unless we copy the entire argument at once (which would require a rather wasteful allocation). The good news is that with this patch the kernel no longer relies on this strnlen_user() value for anything beyond recording it in the log, we also update it with a trustworthy value whenever possible. Reported-by: Pengfei Wang Cc: Signed-off-by: Paul Moore Signed-off-by: Sasha Levin

Fix broken audit tests for exec arg len

2016-08-20T03:07:58Z

[ Upstream commit 45820c294fe1b1a9df495d57f40585ef2d069a39 ] The "fix" in commit 0b08c5e5944 ("audit: Fix check of return value of strnlen_user()") didn't fix anything, it broke things. As reported by Steven Rostedt: "Yes, strnlen_user() returns 0 on fault, but if you look at what len is set to, than you would notice that on fault len would be -1" because we just subtracted one from the return value. So testing against 0 doesn't test for a fault condition, it tests against a perfectly valid empty string. Also fix up the usual braindamage wrt using WARN_ON() inside a conditional - make it part of the conditional and remove the explicit unlikely() (which is already part of the WARN_ON*() logic, exactly so that you don't have to write unreadable code. Reported-and-tested-by: Steven Rostedt Cc: Jan Kara Cc: Paul Moore Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

audit: Fix check of return value of strnlen_user()

2016-08-20T03:07:58Z

[ Upstream commit 0b08c5e59441d08ab4b5e72afefd5cd98a4d83df ] strnlen_user() returns 0 when it hits fault, not -1. Fix the test in audit_log_single_execve_arg(). Luckily this shouldn't ever happen unless there's a kernel bug so it's mostly a cosmetic fix. CC: Paul Moore Signed-off-by: Jan Kara Signed-off-by: Paul Moore Signed-off-by: Sasha Levin

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-04-27T00:22:07Z

Pull fourth vfs update from Al Viro: "d_inode() annotations from David Howells (sat in for-next since before the beginning of merge window) + four assorted fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: RCU pathwalk breakage when running into a symlink overmounting something fix I_DIO_WAKEUP definition direct-io: only inc/dec inode->i_dio_count for file systems fs/9p: fix readdir() VFS: assorted d_backing_inode() annotations VFS: fs/inode.c helpers: d_inode() annotations VFS: fs/cachefiles: d_backing_inode() annotations VFS: fs library helpers: d_inode() annotations VFS: assorted weird filesystems: d_inode() annotations VFS: normal filesystems (and lustre): d_inode() annotations VFS: security/: d_inode() annotations VFS: security/: d_backing_inode() annotations VFS: net/: d_inode() annotations VFS: net/unix: d_backing_inode() annotations VFS: kernel/: d_inode() annotations VFS: audit: d_backing_inode() annotations VFS: Fix up some ->d_inode accesses in the chelsio driver VFS: Cachefiles should perform fs modifications on the top layer only VFS: AF_UNIX sockets should call mknod on the top layer only

Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit

2015-04-22T21:49:23Z

Pull audit fixes from Paul Moore: "Seven audit patches for v4.1, all bug fixes. The largest, and perhaps most significant commit helps resolve some memory pressure issues related to the inode cache and audit, there are also a few small commits which help resolve some timing issues with the audit log queue, and the rest fall into the always popular "code clean-up" category. In general, nothing really substantial, just a nice set of maintenance patches" * 'upstream' of git://git.infradead.org/users/pcmoore/audit: audit: Remove condition which always evaluates to false audit: reduce mmap_sem hold for mm->exe_file audit: consolidate handling of mm->exe_file audit: code clean up audit: don't reset working wait time accidentally with auditd audit: don't lose set wait time on first successful call to audit_log_start() audit: move the tree pruning to a dedicated thread

VFS: audit: d_backing_inode() annotations

2015-04-15T19:06:55Z

Signed-off-by: David Howells Signed-off-by: Al Viro

audit: consolidate handling of mm->exe_file

2015-02-23T21:55:47Z

This patch adds a audit_log_d_path_exe() helper function to share how we handle auditing of the exe_file's path. Used by both audit and auditsc. No functionality is changed. Signed-off-by: Davidlohr Bueso [PM: tweaked subject line] Signed-off-by: Paul Moore

Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-02-17T23:27:47Z

Pull getname/putname updates from Al Viro: "Rework of getname/getname_kernel/etc., mostly from Paul Moore. Gets rid of quite a pile of kludges between namei and audit..." * 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: audit: replace getname()/putname() hacks with reference counters audit: fix filename matching in __audit_inode() and __audit_inode_child() audit: enable filename recording via getname_kernel() simpler calling conventions for filename_mountpoint() fs: create proper filename objects using getname_kernel() fs: rework getname_kernel to handle up to PATH_MAX sized filenames cut down the number of do_path_lookup() callers

file->f_path.dentry is pinned down for as long as the file is open...

2015-01-26T04:16:27Z

Signed-off-by: Al Viro

audit: replace getname()/putname() hacks with reference counters

2015-01-23T05:23:58Z

In order to ensure that filenames are not released before the audit subsystem is done with the strings there are a number of hacks built into the fs and audit subsystems around getname() and putname(). To say these hacks are "ugly" would be kind. This patch removes the filename hackery in favor of a more conventional reference count based approach. The diffstat below tells most of the story; lots of audit/fs specific code is replaced with a traditional reference count based approach that is easily understood, even by those not familiar with the audit and/or fs subsystems. CC: viro@zeniv.linux.org.uk CC: linux-fsdevel@vger.kernel.org Signed-off-by: Paul Moore Signed-off-by: Al Viro