user/sven/linux.git/kernel/audit_watch.c, branch v4.14.99

audit: fix use-after-free in audit_add_watch

2018-09-26T06:38:09Z

[ Upstream commit baa2a4fdd525c8c4b0f704d20457195b29437839 ] audit_add_watch stores locally krule->watch without taking a reference on watch. Then, it calls audit_add_to_parent, and uses the watch stored locally. Unfortunately, it is possible that audit_add_to_parent updates krule->watch. When it happens, it also drops a reference of watch which could free the watch. How to reproduce (with KASAN enabled): auditctl -w /etc/passwd -F success=0 -k test_passwd auditctl -w /etc/passwd -F success=1 -k test_passwd2 The second call to auditctl triggers the use-after-free, because audit_to_parent updates krule->watch to use a previous existing watch and drops the reference to the newly created watch. To fix the issue, we grab a reference of watch and we release it at the end of the function. Signed-off-by: Ronny Chevalier Reviewed-by: Richard Guy Briggs Signed-off-by: Paul Moore Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Merge tag 'audit-pr-20170816' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

2017-08-16T23:48:34Z

Pull audit fixes from Paul Moore: "Two small fixes to the audit code, both explained well in the respective patch descriptions, but the quick summary is one use-after-free fix, and one silly fanotify notification flag fix" * tag 'audit-pr-20170816' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: Receive unmount event audit: Fix use after free in audit_remove_watch_rule()

audit: Receive unmount event

2017-08-15T20:03:00Z

Although audit_watch_handle_event() can handle FS_UNMOUNT event, it is not part of AUDIT_FS_WATCH mask and thus such event never gets to audit_watch_handle_event(). Thus fsnotify marks are deleted by fsnotify subsystem on unmount without audit being notified about that which leads to a strange state of existing audit rules with dead fsnotify marks. Add FS_UNMOUNT to the mask of events to be received so that audit can clean up its state accordingly. Signed-off-by: Jan Kara Signed-off-by: Paul Moore

audit: Fix use after free in audit_remove_watch_rule()

2017-08-15T19:58:17Z

audit_remove_watch_rule() drops watch's reference to parent but then continues to work with it. That is not safe as parent can get freed once we drop our reference. The following is a trivial reproducer: mount -o loop image /mnt touch /mnt/file auditctl -w /mnt/file -p wax umount /mnt auditctl -D Grab our own reference in audit_remove_watch_rule() earlier to make sure mark does not get freed under us. CC: stable@vger.kernel.org Reported-by: Tony Jones Signed-off-by: Jan Kara Tested-by: Tony Jones Signed-off-by: Paul Moore

Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2017-05-03T18:05:15Z

Pull fsnotify updates from Jan Kara: "The branch contains mainly a rework of fsnotify infrastructure fixing a shortcoming that we have waited for response to fanotify permission events with SRCU read lock held and when the process consuming events was slow to respond the kernel has stalled. It also contains several cleanups of unnecessary indirections in fsnotify framework and a bugfix from Amir fixing leakage of kernel internal errno to userspace" * 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (37 commits) fanotify: don't expose EOPENSTALE to userspace fsnotify: remove a stray unlock fsnotify: Move ->free_mark callback to fsnotify_ops fsnotify: Add group pointer in fsnotify_init_mark() fsnotify: Drop inode_mark.c fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark() fsnotify: Remove fsnotify_detach_group_marks() fsnotify: Rename fsnotify_clear_marks_by_group_flags() fsnotify: Inline fsnotify_clear_{inode|vfsmount}_mark_group() fsnotify: Remove fsnotify_recalc_{inode|vfsmount}_mask() fsnotify: Remove fsnotify_set_mark_{,ignored_}mask_locked() fanotify: Release SRCU lock when waiting for userspace response fsnotify: Pass fsnotify_iter_info into handle_event handler fsnotify: Provide framework for dropping SRCU lock in ->handle_event fsnotify: Remove special handling of mark destruction on group shutdown fsnotify: Detach mark from object list when last reference is dropped fsnotify: Move queueing of mark for destruction into fsnotify_put_mark() inotify: Do not drop mark reference under idr_lock fsnotify: Free fsnotify_mark_connector when there is no mark attached fsnotify: Lock object list with connector lock ...

audit: convert audit_watch.count from atomic_t to refcount_t

2017-05-02T14:16:05Z

refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor [PM: fix subject line, add #include] Signed-off-by: Paul Moore

audit: remove unnecessary semicolon in audit_watch_handle_event()

2017-05-02T14:16:04Z

The excess ; after the closing parenthesis is just code-noise it has no and can be removed. Signed-off-by: Nicholas Mc Guire [PM: tweaked subject line] Signed-off-by: Paul Moore

fsnotify: Move ->free_mark callback to fsnotify_ops

2017-04-10T15:37:36Z

Pointer to ->free_mark callback unnecessarily occupies one long in each fsnotify_mark although they are the same for all marks from one notification group. Move the callback pointer to fsnotify_ops. Reviewed-by: Miklos Szeredi Reviewed-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: Add group pointer in fsnotify_init_mark()

2017-04-10T15:37:36Z

Currently we initialize mark->group only in fsnotify_add_mark_lock(). However we will need to access fsnotify_ops of corresponding group from fsnotify_put_mark() so we need mark->group initialized earlier. Do that in fsnotify_init_mark() which has a consequence that once fsnotify_init_mark() is called on a mark, the mark has to be destroyed by fsnotify_put_mark(). Reviewed-by: Miklos Szeredi Reviewed-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark()

2017-04-10T15:37:36Z

These are very thin wrappers, just remove them. Drop fs/notify/vfsmount_mark.c as it is empty now. Reviewed-by: Miklos Szeredi Reviewed-by: Amir Goldstein Signed-off-by: Jan Kara