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
...
struct timespec is not y2038 safe. Audit timestamps are recorded in string format into an audit buffer for a given context. These mark the entry timestamps for the syscalls. Use y2038 safe struct timespec64 to represent the times. The log strings can handle this transition as strings can hold upto 1024 characters. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
Currently we free fsnotify_mark_connector structure only when inode / vfsmount is getting freed. This can however impose noticeable memory overhead when marks get attached to inodes only temporarily. So free the connector structure once the last mark is detached from the object. Since notification infrastructure can be working with the connector under the protection of fsnotify_mark_srcu, we have to be careful and free the fsnotify_mark_connector only after SRCU period passes. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Currently notification marks are attached to object (inode or vfsmnt) by a hlist_head in the object. The list is also protected by a spinlock in the object. So while there is any mark attached to the list of marks, the object must be pinned in memory (and thus e.g. last iput() deleting inode cannot happen). Also for list iteration in fsnotify() to work, we must hold fsnotify_mark_srcu lock so that mark itself and mark->obj_list.next cannot get freed. Thus we are required to wait for response to fanotify events from userspace process with fsnotify_mark_srcu lock held. That causes issues when userspace process is buggy and does not reply to some event - basically the whole notification subsystem gets eventually stuck. So to be able to drop fsnotify_mark_srcu lock while waiting for response, we have to pin the mark in memory and make sure it stays in the object list (as removing the mark waiting for response could lead to lost notification events for groups later in the list). However we don't want inode reclaim to block on such mark as that would lead to system just locking up elsewhere. This commit is the first in the series that paves way towards solving these conflicting lifetime needs. Instead of anchoring the list of marks directly in the object, we anchor it in a dedicated structure (fsnotify_mark_connector) and just point to that structure from the object. The following commits will also add spinlock protecting the list and object pointer to the structure. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Commit 5b52330bbfe6 ("audit: fix auditd/kernel connection state
tracking") made inlining audit_signal_info() a bit pointless as
it was always calling into auditd_test_task() so let's remove the
inline function in kernel/audit.h and convert __audit_signal_info()
in kernel/auditsc.c into audit_signal_info().
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
What started as a rather straightforward race condition reported by Dmitry using the syzkaller fuzzer ended up revealing some major problems with how the audit subsystem managed its netlink sockets and its connection with the userspace audit daemon. Fixing this properly had quite the cascading effect and what we are left with is this rather large and complicated patch. My initial goal was to try and decompose this patch into multiple smaller patches, but the way these changes are intertwined makes it difficult to split these changes into meaningful pieces that don't break or somehow make things worse for the intermediate states. The patch makes a number of changes, but the most significant are highlighted below: * The auditd tracking variables, e.g. audit_sock, are now gone and replaced by a RCU/spin_lock protected variable auditd_conn which is a structure containing all of the auditd tracking information. * We no longer track the auditd sock directly, instead we track it via the network namespace in which it resides and we use the audit socket associated with that namespace. In spirit, this is what the code was trying to do prior to this patch (at least I think that is what the original authors intended), but it was done rather poorly and added a layer of obfuscation that only masked the underlying problems. * Big backlog queue cleanup, again. In v4.10 we made some pretty big changes to how the audit backlog queues work, here we haven't changed the queue design so much as cleaned up the implementation. Brought about by the locking changes, we've simplified kauditd_thread() quite a bit by consolidating the queue handling into a new helper function, kauditd_send_queue(), which allows us to eliminate a lot of very similar code and makes the looping logic in kauditd_thread() clearer. * All netlink messages sent to auditd are now sent via auditd_send_unicast_skb(). Other than just making sense, this makes the lock handling easier. * Change the audit_log_start() sleep behavior so that we never sleep on auditd events (unchanged) or if the caller is holding the audit_cmd_mutex (changed). Previously we didn't sleep if the caller was auditd or if the message type fell between a certain range; the type check was a poor effort of doing what the cmd_mutex check now does. Richard Guy Briggs originally proposed not sleeping the cmd_mutex owner several years ago but his patch wasn't acceptable at the time. At least the idea lives on here. * A problem with the lost record counter has been resolved. Steve Grubb and I both happened to notice this problem and according to some quick testing by Steve, this problem goes back quite some time. It's largely a harmless problem, although it may have left some careful sysadmins quite puzzled. Cc: <stable@vger.kernel.org> # 4.10.x- Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull audit updates from Paul Moore:
"The audit changes for v4.11 are relatively small compared to what we
did for v4.10, both in terms of size and impact.
- two patches from Steve tweak the formatting for some of the audit
records to make them more consistent with other audit records.
- three patches from Richard record the name of a module on module
load, fix the logging of sockaddr information when using
socketcall() on 32-bit systems, and add the ability to reset
audit's lost record counter.
- my lone patch just fixes an annoying style nit that I was reminded
about by one of Richard's patches.
All these patches pass our test suite"
* 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit:
audit: remove unnecessary curly braces from switch/case statements
audit: log module name on init_module
audit: log 32-bit socketcalls
audit: add feature audit_lost reset
audit: Make AUDIT_ANOM_ABEND event normalized
audit: Make AUDIT_KERNEL event conform to the specification
Signed-off-by: Paul Moore <paul@paul-moore.com>
This adds a new auxiliary record MODULE_INIT to the SYSCALL event. We get finit_module for free since it made most sense to hook this in to load_module(). https://github.com/linux-audit/audit-kernel/issues/7 https://github.com/linux-audit/audit-kernel/wiki/RFE-Module-Load-Record-Format Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Acked-by: Jessica Yu <jeyu@redhat.com> [PM: corrected links in the commit description] Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull audit updates from Paul Moore:
"After the small number of patches for v4.9, we've got a much bigger
pile for v4.10.
The bulk of these patches involve a rework of the audit backlog queue
to enable us to move the netlink multicasting out of the task/thread
that generates the audit record and into the kernel thread that emits
the record (just like we do for the audit unicast to auditd).
While we were playing with the backlog queue(s) we fixed a number of
other little problems with the code, and from all the testing so far
things look to be in much better shape now. Doing this also allowed us
to re-enable disabling IRQs for some netns operations ("netns: avoid
disabling irq for netns id").
The remaining patches fix some small problems that are well documented
in the commit descriptions, as well as adding session ID filtering
support"
* 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit:
audit: use proper refcount locking on audit_sock
netns: avoid disabling irq for netns id
audit: don't ever sleep on a command record/message
audit: handle a clean auditd shutdown with grace
audit: wake up kauditd_thread after auditd registers
audit: rework audit_log_start()
audit: rework the audit queue handling
audit: rename the queues and kauditd related functions
audit: queue netlink multicast sends just like we do for unicast sends
audit: fixup audit_init()
audit: move kaudit thread start from auditd registration to kaudit init (#2)
audit: add support for session ID user filter
audit: fix formatting of AUDIT_CONFIG_CHANGE events
audit: skip sessionid sentinel value when auto-incrementing
audit: tame initialization warning len_abuf in audit_log_execve_info
audit: less stack usage for /proc/*/loginuid