user/sven/linux.git/kernel/audit_watch.c, branch v4.14.331

audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare()

2023-11-28T16:45:44Z

commit 969d90ec212bae4b45bf9d21d7daa30aa6cf055e upstream. eBPF can end up calling into the audit code from some odd places, and some of these places don't have @current set properly so we end up tripping the `WARN_ON_ONCE(!current->mm)` near the top of `audit_exe_compare()`. While the basic `!current->mm` check is good, the `WARN_ON_ONCE()` results in some scary console messages so let's drop that and just do the regular `!current->mm` check to avoid problems. Cc: Fixes: 47846d51348d ("audit: don't take task_lock() in audit_exe_compare() code path") Reported-by: Artem Savkov Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

audit: don't take task_lock() in audit_exe_compare() code path

2023-11-28T16:45:44Z

commit 47846d51348dd62e5231a83be040981b17c955fa upstream. The get_task_exe_file() function locks the given task with task_lock() which when used inside audit_exe_compare() can cause deadlocks on systems that generate audit records when the task_lock() is held. We resolve this problem with two changes: ignoring those cases where the task being audited is not the current task, and changing our approach to obtaining the executable file struct to not require task_lock(). With the intent of the audit exe filter being to filter on audit events generated by processes started by the specified executable, it makes sense that we would only want to use the exe filter on audit records associated with the currently executing process, e.g. @current. If we are asked to filter records using a non-@current task_struct we can safely ignore the exe filter without negatively impacting the admin's expectations for the exe filter. Knowing that we only have to worry about filtering the currently executing task in audit_exe_compare() we can do away with the task_lock() and call get_mm_exe_file() with @current->mm directly. Cc: Fixes: 5efc244346f9 ("audit: fix exe_file access in audit_exe_compare") Reported-by: Andreas Steinmetz Reviewed-by: John Johansen Reviewed-by: Mateusz Guzik Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

audit: CONFIG_CHANGE don't log internal bookkeeping as an event

2020-10-01T11:12:33Z

[ Upstream commit 70b3eeed49e8190d97139806f6fbaf8964306cdb ] Common Criteria calls out for any action that modifies the audit trail to be recorded. That usually is interpreted to mean insertion or removal of rules. It is not required to log modification of the inode information since the watch is still in effect. Additionally, if the rule is a never rule and the underlying file is one they do not want events for, they get an event for this bookkeeping update against their wishes. Since no device/inode info is logged at insertion and no device/inode information is logged on update, there is nothing meaningful being communicated to the admin by the CONFIG_CHANGE updated_rules event. One can assume that the rule was not "modified" because it is still watching the intended target. If the device or inode cannot be resolved, then audit_panic is called which is sufficient. The correct resolution is to drop logging config_update events since the watch is still in effect but just on another unknown inode. Signed-off-by: Steve Grubb Signed-off-by: Paul Moore Signed-off-by: Sasha Levin

audit_get_nd(): don't unlock parent too early

2019-12-17T19:37:27Z

[ Upstream commit 69924b89687a2923e88cc42144aea27868913d0e ] if the child has been negative and just went positive under us, we want coherent d_is_positive() and ->d_inode. Don't unlock the parent until we'd done that work... Signed-off-by: Al Viro Signed-off-by: Sasha Levin

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