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2017-06-14audit: fix the RCU locking for the auditd_connection structurePaul Moore
commit 48d0e023af9799cd7220335baf8e3ba61eeafbeb upstream. Cong Wang correctly pointed out that the RCU read locking of the auditd_connection struct was wrong, this patch correct this by adopting a more traditional, and correct RCU locking model. This patch is heavily based on an earlier prototype by Cong Wang. Reported-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-10audit: make sure we don't let the retry queue grow without boundsPaul Moore
The retry queue is intended to provide a temporary buffer in the case of transient errors when communicating with auditd, it is not meant as a long life queue, that functionality is provided by the hold queue. This patch fixes a problem identified by Seth where the retry queue could grow uncontrollably if an auditd instance did not connect to the kernel to drain the queues. This commit fixes this by doing the following: * Make sure we always call auditd_reset() if we decide the connection with audit is really dead. There were some cases in kauditd_hold_skb() where we did not reset the connection, this patch relocates the reset calls to kauditd_thread() so all the error conditions are caught and the connection reset. As a side effect, this means we could move auditd_reset() and get rid of the forward definition at the top of kernel/audit.c. * We never checked the status of the auditd connection when processing the main audit queue which meant that the retry queue could grow unchecked. This patch adds a call to auditd_reset() after the main queue has been processed if auditd is not connected, the auditd_reset() call will make sure the retry and hold queues are correctly managed/flushed so that the retry queue remains reasonable. Cc: <stable@vger.kernel.org> # 4.10.x-: 5b52330bbfe6 Reported-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-21audit: fix auditd/kernel connection state trackingPaul Moore
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>
2017-02-21Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
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
2017-01-18audit: add feature audit_lost resetRichard Guy Briggs
Add a method to reset the audit_lost value. An AUDIT_SET message with the AUDIT_STATUS_LOST flag set by itself will return a positive value repesenting the current audit_lost value and reset the counter to zero. If AUDIT_STATUS_LOST is not the only flag set, the reset command will be ignored. The value sent with the command is ignored. The return value will be the +ve lost value at reset time. An AUDIT_CONFIG_CHANGE message will be queued to the listening audit daemon. The message will be a standard CONFIG_CHANGE message with the fields "lost=0" and "old=" with the latter containing the value of audit_lost at reset time. See: https://github.com/linux-audit/audit-kernel/issues/3 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Acked-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "In this pile: - autofs-namespace series - dedupe stuff - more struct path constification" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features ocfs2: charge quota for reflinked blocks ocfs2: fix bad pointer cast ocfs2: always unlock when completing dio writes ocfs2: don't eat io errors during _dio_end_io_write ocfs2: budget for extent tree splits when adding refcount flag ocfs2: prohibit refcounted swapfiles ocfs2: add newlines to some error messages ocfs2: convert inode refcount test to a helper simple_write_end(): don't zero in short copy into uptodate exofs: don't mess with simple_write_{begin,end} 9p: saner ->write_end() on failing copy into non-uptodate page fix gfs2_stuffed_write_end() on short copies fix ceph_write_end() nfs_write_end(): fix handling of short copies vfs: refactor clone/dedupe_file_range common functions fs: try to clone files first in vfs_copy_file_range vfs: misc struct path constification namespace.c: constify struct path passed to a bunch of primitives quota: constify struct path in quota_on ...
2016-12-14Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
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
2016-12-14audit: Make AUDIT_KERNEL event conform to the specificationSteve Grubb
The AUDIT_KERNEL event is not following name=value format. This causes some information to get lost. The event has been reformatted to follow the convention. Additionally the audit_enabled value was added for troubleshooting purposes. The following is an example of the new event: type=KERNEL audit(1480621249.833:1): state=initialized audit_enabled=0 res=1 Signed-off-by: Steve Grubb <sgrubb@redhat.com> [PM: commit tweaks to make checkpatch.pl happy] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: use proper refcount locking on audit_sockRichard Guy Briggs
Resetting audit_sock appears to be racy. audit_sock was being copied and dereferenced without using a refcount on the source sock. Bump the refcount on the underlying sock when we store a refrence in audit_sock and release it when we reset audit_sock. audit_sock modification needs the audit_cmd_mutex. See: https://lkml.org/lkml/2016/11/26/232 Thanks to Eric Dumazet <edumazet@google.com> and Cong Wang <xiyou.wangcong@gmail.com> on ideas how to fix it. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com> [PM: fixed the comment block text formatting for auditd_reset()] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: don't ever sleep on a command record/messagePaul Moore
Sleeping on a command record/message in audit_log_start() could slow something, e.g. auditd, from doing something important, e.g. clean shutdown, which could present problems on a heavily loaded system. This patch allows tasks to bypass any queue restrictions if they are logging a command record/message. Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: handle a clean auditd shutdown with gracePaul Moore
When auditd stops cleanly it sets 'auditd_pid' to 0 with an AUDIT_SET message, in this case we should reset our backlog queues via the auditd_reset() function. This patch also adds a 'auditd_pid' check to the top of kauditd_send_unicast_skb() so we can fail quicker. Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: wake up kauditd_thread after auditd registersPaul Moore
This patch was suggested by Richard Briggs back in 2015, see the link to the mail archive below. Unfortunately, that patch is no longer even remotely valid due to other changes to the code. * https://www.redhat.com/archives/linux-audit/2015-October/msg00075.html Suggested-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: rework audit_log_start()Paul Moore
The backlog queue handling in audit_log_start() is a little odd with some questionable design decisions, this patch attempts to rectify this with the following changes: * Never make auditd wait, ignore any backlog limits as we need auditd awake so it can drain the backlog queue. * When we hit a backlog limit and start dropping records, don't wake all the tasks sleeping on the backlog, that's silly. Instead, let kauditd_thread() take care of waking everyone once it has had a chance to drain the backlog queue. * Don't keep a global backlog timeout countdown, make it per-task. A per-task timer means we won't have all the sleeping tasks waking at the same time and hammering on an already stressed backlog queue. Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: rework the audit queue handlingPaul Moore
The audit record backlog queue has always been a bit of a mess, and the moving the multicast send into kauditd_thread() from audit_log_end() only makes things worse. This patch attempts to fix the backlog queue with a better design that should hold up better under load and have less of a performance impact at syscall invocation time. While it looks like there is a log going on in this patch, the main change is the move from a single backlog queue to three queues: * A queue for holding records generated from audit_log_end() that haven't been consumed by kauditd_thread() (audit_queue). * A queue for holding records that have been sent via multicast but had a temporary failure when sending via unicast and need a resend (audit_retry_queue). * A queue for holding records that haven't been sent via unicast because no one is listening (audit_hold_queue). Special care is taken in this patch to ensure that the proper record ordering is preserved, e.g. we send everything in the hold queue first, then the retry queue, and finally the main queue. Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: rename the queues and kauditd related functionsPaul Moore
The audit queue names can be shortened and the record sending helpers associated with the kauditd task could be named better, do these small cleanups now to make life easier once we start reworking the queues and kauditd code. Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: queue netlink multicast sends just like we do for unicast sendsPaul Moore
Sending audit netlink multicast messages is bad for all the same reasons that sending audit netlink unicast messages is bad, so this patch reworks things so that we don't do the multicast send in audit_log_end(), we do it from the dedicated kauditd_thread thread just as we do for unicast messages. See the GitHub issues below for more information/history: * https://github.com/linux-audit/audit-kernel/issues/23 * https://github.com/linux-audit/audit-kernel/issues/22 Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: fixup audit_init()Paul Moore
Make sure everything is initialized before we start the kauditd_thread and don't emit the "initialized" record until everything is finished. We also panic with a descriptive message if we can't start the kauditd_thread. Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14audit: move kaudit thread start from auditd registration to kaudit init (#2)Richard Guy Briggs
Richard made this change some time ago but Eric backed it out because the rest of the supporting code wasn't ready. In order to move the netlink multicast send to kauditd_thread we need to ensure the kauditd_thread is always running, so restore commit 6ff5e459 ("audit: move kaudit thread start from auditd registration to kaudit init"). Signed-off-by: Richard Guy Briggs <rbriggs@redhat.com> [PM: brought forward and merged based on Richard's old patch] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-05audit_log_{name,link_denied}: constify struct pathAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-01audit: remove useless synchronize_net()WANG Cong
netlink kernel socket is protected by refcount, not RCU. Its rcv path is neither protected by RCU. So the synchronize_net() is just pointless. Cc: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18netns: make struct pernet_operations::id unsigned intAlexey Dobriyan
Make struct pernet_operations::id unsigned. There are 2 reasons to do so: 1) This field is really an index into an zero based array and thus is unsigned entity. Using negative value is out-of-bound access by definition. 2) On x86_64 unsigned 32-bit data which are mixed with pointers via array indexing or offsets added or subtracted to pointers are preffered to signed 32-bit data. "int" being used as an array index needs to be sign-extended to 64-bit before being used. void f(long *p, int i) { g(p[i]); } roughly translates to movsx rsi, esi mov rdi, [rsi+...] call g MOVSX is 3 byte instruction which isn't necessary if the variable is unsigned because x86_64 is zero extending by default. Now, there is net_generic() function which, you guessed it right, uses "int" as an array index: static inline void *net_generic(const struct net *net, int id) { ... ptr = ng->ptr[id - 1]; ... } And this function is used a lot, so those sign extensions add up. Patch snipes ~1730 bytes on allyesconfig kernel (without all junk messing with code generation): add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) Unfortunately some functions actually grow bigger. This is a semmingly random artefact of code generation with register allocator being used differently. gcc decides that some variable needs to live in new r8+ registers and every access now requires REX prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be used which is longer than [r8] However, overall balance is in negative direction: add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) function old new delta nfsd4_lock 3886 3959 +73 tipc_link_build_proto_msg 1096 1140 +44 mac80211_hwsim_new_radio 2776 2808 +32 tipc_mon_rcv 1032 1058 +26 svcauth_gss_legacy_init 1413 1429 +16 tipc_bcbase_select_primary 379 392 +13 nfsd4_exchange_id 1247 1260 +13 nfsd4_setclientid_confirm 782 793 +11 ... put_client_renew_locked 494 480 -14 ip_set_sockfn_get 730 716 -14 geneve_sock_add 829 813 -16 nfsd4_sequence_done 721 703 -18 nlmclnt_lookup_host 708 686 -22 nfsd4_lockt 1085 1063 -22 nfs_get_client 1077 1050 -27 tcf_bpf_init 1106 1076 -30 nfsd4_encode_fattr 5997 5930 -67 Total: Before=154856051, After=154854321, chg -0.00% Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-04Merge branch 'stable-4.9' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "Another relatively small pull request for v4.9 with just two patches. The patch from Richard updates the list of features we support and report back to userspace; this should have been sent earlier with the rest of the v4.8 patches but it got lost in my inbox. The second patch fixes a problem reported by our Android friends where we weren't very consistent in recording PIDs" * 'stable-4.9' of git://git.infradead.org/users/pcmoore/audit: audit: add exclude filter extension to feature bitmap audit: consistently record PIDs with task_tgid_nr()
2016-08-30audit: consistently record PIDs with task_tgid_nr()Paul Moore
Unfortunately we record PIDs in audit records using a variety of methods despite the correct way being the use of task_tgid_nr(). This patch converts all of these callers, except for the case of AUDIT_SET in audit_receive_msg() (see the comment in the code). Reported-by: Jeff Vander Stoep <jeffv@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-07-29Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "Six audit patches for 4.8. There are a couple of style and minor whitespace tweaks for the logs, as well as a minor fixup to catch errors on user filter rules, however the major improvements are a fix to the s390 syscall argument masking code (reviewed by the nice s390 folks), some consolidation around the exclude filtering (less code, always a win), and a double-fetch fix for recording the execve arguments" * 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit: audit: fix a double fetch in audit_log_single_execve_arg() audit: fix whitespace in CWD record audit: add fields to exclude filter by reusing user filter s390: ensure that syscall arguments are properly masked on s390 audit: fix some horrible switch statement style crimes audit: fixup: log on errors from filter user rules
2016-06-29Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit fixes from Paul Moore: "Two small patches to fix audit problems in 4.7-rcX: the first fixes a potential kref leak, the second removes some header file noise. The first is an important bug fix that really should go in before 4.7 is released, the second is not critical, but falls into the very-nice- to-have category so I'm including in the pull request. Both patches are straightforward, self-contained, and pass our testsuite without problem" * 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit: audit: move audit_get_tty to reduce scope and kabi changes audit: move calcs after alloc and check when logging set loginuid
2016-06-28audit: move audit_get_tty to reduce scope and kabi changesRichard Guy Briggs
The only users of audit_get_tty and audit_put_tty are internal to audit, so move it out of include/linux/audit.h to kernel.h and create a proper function rather than inlining it. This also reduces kABI changes. Suggested-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: line wrapped description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27audit: add fields to exclude filter by reusing user filterRichard Guy Briggs
RFE: add additional fields for use in audit filter exclude rules https://github.com/linux-audit/audit-kernel/issues/5 Re-factor and combine audit_filter_type() with audit_filter_user() to use audit_filter_user_rules() to enable the exclude filter to additionally filter on PID, UID, GID, AUID, LOGINUID_SET, SUBJ_*. The process of combining the similar audit_filter_user() and audit_filter_type() functions, required inverting the meaning and including the ALWAYS action of the latter. Include audit_filter_user_rules() into audit_filter(), removing unneeded logic in the process. Keep the check to quit early if the list is empty. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: checkpatch.pl fixes - whitespace damage, wrapped description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-05-18Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "Four small audit patches for 4.7. Two are simple cleanups around the audit thread management code, one adds a tty field to AUDIT_LOGIN events, and the final patch makes tty_name() usable regardless of CONFIG_TTY. Nothing controversial, and it all passes our regression test" * 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit: tty: provide tty_name() even without CONFIG_TTY audit: add tty field to LOGIN event audit: we don't need to __set_current_state(TASK_RUNNING) audit: cleanup prune_tree_thread
2016-04-26audit: add tty field to LOGIN eventRichard Guy Briggs
The tty field was missing from AUDIT_LOGIN events. Refactor code to create a new function audit_get_tty(), using it to replace the call in audit_log_task_info() and to add it to audit_log_set_loginuid(). Lock and bump the kref to protect it, adding audit_put_tty() alias to decrement it. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-04-04audit: we don't need to __set_current_state(TASK_RUNNING)Paul Moore
Remove the calls to __set_current_state() to mark the task as running and do some related cleanup in wait_for_auditd() to limit the amount of work we do when we aren't going to reschedule the current task. Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-03-19Merge branch 'stable-4.6' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "A small set of patches for audit this time; just three in total and one is a spelling fix. The two patches with actual content are designed to help prevent new instances of auditd from displacing an existing, functioning auditd and to generate a log of the attempt. Not to worry, dead/stuck auditd instances can still be replaced by a new instance without problem. Nothing controversial, and everything passes our regression suite" * 'stable-4.6' of git://git.infradead.org/users/pcmoore/audit: audit: Fix typo in comment audit: log failed attempts to change audit_pid configuration audit: stop an old auditd being starved out by a new auditd
2016-01-27tty: audit: Handle tty audit enable atomicallyPeter Hurley
The audit_tty and audit_tty_log_passwd fields are actually bool values, so merge into single memory location to access atomically. NB: audit log operations may still occur after tty audit is disabled which is consistent with the existing functionality Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Combine push functionsPeter Hurley
tty_audit_push() and tty_audit_push_current() perform identical tasks; eliminate the tty_audit_push() implementation and the tty_audit_push_current() name. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-25audit: log failed attempts to change audit_pid configurationRichard Guy Briggs
Failed attempts to change the audit_pid configuration are not presently logged. One case is an attempt to starve an old auditd by starting up a new auditd when the old one is still alive and active. The other case is an attempt to orphan a new auditd when an old auditd shuts down. Log both as AUDIT_CONFIG_CHANGE messages with failure result. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-25audit: stop an old auditd being starved out by a new auditdRichard Guy Briggs
Nothing prevents a new auditd starting up and replacing a valid audit_pid when an old auditd is still running, effectively starving out the old auditd since audit_pid no longer points to the old valid auditd. If no message to auditd has been attempted since auditd died unnaturally or got killed, audit_pid will still indicate it is alive. There isn't an easy way to detect if an old auditd is still running on the existing audit_pid other than attempting to send a message to see if it fails. An -ECONNREFUSED almost certainly means it disappeared and can be replaced. Other errors are not so straightforward and may indicate transient problems that will resolve themselves and the old auditd will recover. Yet others will likely need manual intervention for which a new auditd will not solve the problem. Send a new message type (AUDIT_REPLACE) to the old auditd containing a u32 with the PID of the new auditd. If the audit replace message succeeds (or doesn't fail with certainty), fail to register the new auditd and return an error (-EEXIST). This is expected to make the patch preventing an old auditd orphaning a new auditd redundant. V3: Switch audit message type from 1000 to 1300 block. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: - EVM gains support for loading an x509 cert from the kernel (EVM_LOAD_X509), into the EVM trusted kernel keyring. - Smack implements 'file receive' process-based permission checking for sockets, rather than just depending on inode checks. - Misc enhancments for TPM & TPM2. - Cleanups and bugfixes for SELinux, Keys, and IMA. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits) selinux: Inode label revalidation performance fix KEYS: refcount bug fix ima: ima_write_policy() limit locking IMA: policy can be updated zero times selinux: rate-limit netlink message warnings in selinux_nlmsg_perm() selinux: export validatetrans decisions gfs2: Invalid security labels of inodes when they go invalid selinux: Revalidate invalid inode security labels security: Add hook to invalidate inode security labels selinux: Add accessor functions for inode->i_security security: Make inode argument of inode_getsecid non-const security: Make inode argument of inode_getsecurity non-const selinux: Remove unused variable in selinux_inode_init_security keys, trusted: seal with a TPM2 authorization policy keys, trusted: select hash algorithm for TPM2 chips keys, trusted: fix: *do not* allow duplicate key options tpm_ibmvtpm: properly handle interrupted packet receptions tpm_tis: Tighten IRQ auto-probing tpm_tis: Refactor the interrupt setup tpm_tis: Get rid of the duplicate IRQ probing code ...
2016-01-13audit: Delete unnecessary checks before two function callsMarkus Elfring
The functions consume_skb() and kfree_skb() test whether their argument is NULL and then return immediately. Thus the tests around their calls are not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> [PM: tweak patch prefix] Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-13audit: wake up threads if queue switched from limited to unlimitedRichard Guy Briggs
If the audit_backlog_limit is changed from a limited value to an unlimited value (zero) while the queue was overflowed, wake up the audit_backlog_wait queue to allow those processes to continue. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-13audit: include auditd's threads in audit_log_start() wait exceptionRichard Guy Briggs
Should auditd spawn threads, allow all members of its thread group to use the audit_backlog_limit reserves to bypass the queue limits too. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: minor upstream merge tweaks] Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-13audit: remove audit_backlog_wait_overflowPaul Moore
It seems much more obvious and readable to simply use "0". Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-13audit: don't needlessly reset valid wait timeRichard Guy Briggs
After auditd has recovered from an overflowed queue, the first process that doesn't use reserves to make it through the queue checks should reset the audit backlog wait time to the configured value. After that, there is no need to keep resetting it. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-12-24security: Make inode argument of inode_getsecid non-constAndreas Gruenbacher
Make the inode argument of the inode_getsecid hook non-const so that we can use it to revalidate invalid security labels. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-11-06mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-04audit: make audit_log_common_recv_msg() a void functionPaul Moore
It always returns zero and no one is checking the return value. Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-11-04audit: removing unused variableSaurabh Sengar
Variable rc in not required as it is just used for unchanged for return, and return is always 0 in the function. Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com> [PM: fixed spelling errors in description] Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-11-04audit: audit_string_contains_control can be booleanYaowei Bai
This patch makes audit_string_contains_control return bool to improve readability due to this particular function only using either one or zero as its return value. Signed-off-by: Yaowei Bai <bywxiaobai@163.com> [PM: tweaked subject line] Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-11-04audit: try harder to send to auditd upon netlink failureRichard Guy Briggs
There are several reports of the kernel losing contact with auditd when it is, in fact, still running. When this happens, kernel syslogs show: "audit: *NO* daemon at audit_pid=<pid>" although auditd is still running, and is apparently happy, listening on the netlink socket. The pid in the "*NO* daemon" message matches the pid of the running auditd process. Restarting auditd solves this. The problem appears to happen randomly, and doesn't seem to be strongly correlated to the rate of audit events being logged. The problem happens fairly regularly (every few days), but not yet reproduced to order. On production kernels, BUG_ON() is a no-op, so any error will trigger this. Commit 34eab0a7cd45 ("audit: prevent an older auditd shutdown from orphaning a newer auditd startup") eliminates one possible cause. This isn't the case here, since the PID in the error message and the PID of the running auditd match. The primary expected cause of error here is -ECONNREFUSED when the audit daemon goes away, when netlink_getsockbyportid() can't find the auditd portid entry in the netlink audit table (or there is no receive function). If -EPERM is returned, that situation isn't likely to be resolved in a timely fashion without administrator intervention. In both cases, reset the audit_pid. This does not rule out a race condition. SELinux is expected to return zero since this isn't an INET or INET6 socket. Other LSMs may have other return codes. Log the error code for better diagnosis in the future. In the case of -ENOMEM, the situation could be temporary, based on local or general availability of buffers. -EAGAIN should never happen since the netlink audit (kernel) socket is set to MAX_SCHEDULE_TIMEOUT. -ERESTARTSYS and -EINTR are not expected since this kernel thread is not expected to receive signals. In these cases (or any other unexpected ones for now), report the error and re-schedule the thread, retrying up to 5 times. v2: Removed BUG_ON(). Moved comma in pr_*() statements. Removed audit_strerror() text. Reported-by: Vipin Rathor <v.rathor@gmail.com> Reported-by: <ctcard@hotmail.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: applied rgb's fixup patch to correct audit_log_lost() format issues] Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-09-08Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit update from Paul Moore: "This is one of the larger audit patchsets in recent history, consisting of eight patches and almost 400 lines of changes. The bulk of the patchset is the new "audit by executable" functionality which allows admins to set an audit watch based on the executable on disk. Prior to this, admins could only track an application by PID, which has some obvious limitations. Beyond the new functionality we also have some refcnt fixes and a few minor cleanups" * 'upstream' of git://git.infradead.org/users/pcmoore/audit: fixup: audit: implement audit by executable audit: implement audit by executable audit: clean simple fsnotify implementation audit: use macros for unset inode and device values audit: make audit_del_rule() more robust audit: fix uninitialized variable in audit_add_rule() audit: eliminate unnecessary extra layer of watch parent references audit: eliminate unnecessary extra layer of watch references
2015-08-06audit: use macros for unset inode and device valuesRichard Guy Briggs
Clean up a number of places were casted magic numbers are used to represent unset inode and device numbers in preparation for the audit by executable path patch set. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: enclosed the _UNSET macros in parentheses for ./scripts/checkpatch] Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-06-27Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "Four small audit patches for v4.2, all bug fixes. Only 10 lines of change this time so very unremarkable, the patch subject lines pretty much tell the whole story" * 'upstream' of git://git.infradead.org/users/pcmoore/audit: audit: Fix check of return value of strnlen_user() audit: obsolete audit_context check is removed in audit_filter_rules() audit: fix for typo in comment to function audit_log_link_denied() lsm: rename duplicate labels in LSM_AUDIT_DATA_TASK audit message type