On the rebase of the following commit on the new seccomp actions_logged
function, one audit_context access was missed.
commit cdfb6b341f
("audit: use inline function to get audit context")
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Recognizing that the audit context is an internal audit value, use an
access function to set the audit context pointer for the task
rather than reaching directly into the task struct to set it.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in audit.h]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Recognizing that the audit context is an internal audit value, use an
access function to retrieve the audit context pointer for the task
rather than reaching directly into the task struct to get it.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in auditsc.c and selinuxfs.c, checkpatch.pl fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Use a macro, "AUDIT_SID_UNSET", to replace each instance of
initialization and comparison to an audit session ID.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Seccomp logging for "handled" actions such as RET_TRAP, RET_TRACE, or
RET_ERRNO can be very noisy for processes that are being audited. This
patch modifies the seccomp logging behavior to treat processes that are
being inspected via the audit subsystem the same as processes that
aren't under inspection. Handled actions will no longer be logged just
because the process is being inspected. Since v4.14, applications have
the ability to request logging of handled actions by using the
SECCOMP_FILTER_FLAG_LOG flag when loading seccomp filters.
With this patch, the logic for deciding if an action will be logged is:
if action == RET_ALLOW:
do not log
else if action not in actions_logged:
do not log
else if action == RET_KILL:
log
else if action == RET_LOG:
log
else if filter-requests-logging:
log
else:
do not log
Reported-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
The decision to log a seccomp action will always be subject to the
value of the kernel.seccomp.actions_logged sysctl, even for processes
that are being inspected via the audit subsystem, in an upcoming patch.
Therefore, we need to emit an audit record on attempts at writing to the
actions_logged sysctl when auditing is enabled.
This patch updates the write handler for the actions_logged sysctl to
emit an audit record on attempts to write to the sysctl. Successful
writes to the sysctl will result in a record that includes a normalized
list of logged actions in the "actions" field and a "res" field equal to
1. Unsuccessful writes to the sysctl will result in a record that
doesn't include the "actions" field and has a "res" field equal to 0.
Not all unsuccessful writes to the sysctl are audited. For example, an
audit record will not be emitted if an unprivileged process attempts to
open the sysctl file for reading since that access control check is not
part of the sysctl's write handler.
Below are some example audit records when writing various strings to the
actions_logged sysctl.
Writing "not-a-real-action", when the kernel.seccomp.actions_logged
sysctl previously was "kill_process kill_thread trap errno trace log",
emits this audit record:
type=CONFIG_CHANGE msg=audit(1525392371.454:120): op=seccomp-logging
actions=? old-actions=kill_process,kill_thread,trap,errno,trace,log
res=0
If you then write "kill_process kill_thread errno trace log", this audit
record is emitted:
type=CONFIG_CHANGE msg=audit(1525392401.645:126): op=seccomp-logging
actions=kill_process,kill_thread,errno,trace,log
old-actions=kill_process,kill_thread,trap,errno,trace,log res=1
If you then write "log log errno trace kill_process kill_thread", which
is unordered and contains the log action twice, it results in the same
actions value as the previous record:
type=CONFIG_CHANGE msg=audit(1525392436.354:132): op=seccomp-logging
actions=kill_process,kill_thread,errno,trace,log
old-actions=kill_process,kill_thread,errno,trace,log res=1
If you then write an empty string to the sysctl, this audit record is
emitted:
type=CONFIG_CHANGE msg=audit(1525392494.413:138): op=seccomp-logging
actions=(none) old-actions=kill_process,kill_thread,errno,trace,log
res=1
No audit records are generated when reading the actions_logged sysctl.
Suggested-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Current implementation of auditing by executable name only implements
the 'equal' operator. This patch extends it to also support the 'not
equal' operator.
See: https://github.com/linux-audit/audit-kernel/issues/53
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
If audit is disabled, who cares if there is a bug indicating syscall in
process or names already recorded. Bail immediately on audit disabled.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
The audit entry filter has been long deprecated with userspace support
finally removed in audit-v2.6.7 and plans to remove kernel support have
existed since kernel-v2.6.31.
Remove it.
Since removing the audit entry filter, test for early return before
setting up any context state.
Passes audit-testsuite.
See: https://github.com/linux-audit/audit-kernel/issues/6
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Merge tag 'audit-pr-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore:
"Another relatively small pull request for audit, nine patches total.
The only real new bit of functionality is the patch from Richard which
adds the ability to filter records based on the filesystem type.
The remainder are bug fixes and cleanups; the bug fix highlights
include:
- ensuring that we properly audit init/PID-1 (me)
- allowing the audit daemon to shutdown the kernel/auditd connection
cleanly by setting the audit PID to zero (Steve)"
* tag 'audit-pr-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: filter PATH records keyed on filesystem magic
Audit: remove unused audit_log_secctx function
audit: Allow auditd to set pid to 0 to end auditing
audit: Add new syscalls to the perm=w filter
audit: use audit_set_enabled() in audit_enable()
audit: convert audit_ever_enabled to a boolean
audit: don't use simple_strtol() anymore
audit: initialize the audit subsystem as early as possible
audit: ensure that 'audit=1' actually enables audit for PID 1
Tracefs or debugfs were causing hundreds to thousands of PATH records to
be associated with the init_module and finit_module SYSCALL records on a
few modules when the following rule was in place for startup:
-a always,exit -F arch=x86_64 -S init_module -F key=mod-load
Provide a method to ignore these large number of PATH records from
overwhelming the logs if they are not of interest. Introduce a new
filter list "AUDIT_FILTER_FS", with a new field type AUDIT_FSTYPE,
which keys off the filesystem 4-octet hexadecimal magic identifier to
filter specific filesystem PATH records.
An example rule would look like:
-a never,filesystem -F fstype=0x74726163 -F key=ignore_tracefs
-a never,filesystem -F fstype=0x64626720 -F key=ignore_debugfs
Arguably the better way to address this issue is to disable tracefs and
debugfs on boot from production systems.
See: https://github.com/linux-audit/audit-kernel/issues/16
See: https://github.com/linux-audit/audit-userspace/issues/8
Test case: https://github.com/linux-audit/audit-testsuite/issues/42
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed the whitespace damage in kernel/auditsc.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>
The fanotify interface allows user space daemons to make access
control decisions. Under common criteria requirements, we need to
optionally record decisions based on policy. This patch adds a bit mask,
FAN_AUDIT, that a user space daemon can 'or' into the response decision
which will tell the kernel that it made a decision and record it.
It would be used something like this in user space code:
response.response = FAN_DENY | FAN_AUDIT;
write(fd, &response, sizeof(struct fanotify_response));
When the syscall ends, the audit system will record the decision as a
AUDIT_FANOTIFY auxiliary record to denote that the reason this event
occurred is the result of an access control decision from fanotify
rather than DAC or MAC policy.
A sample event looks like this:
type=PATH msg=audit(1504310584.332:290): item=0 name="./evil-ls"
inode=1319561 dev=fc:03 mode=0100755 ouid=1000 ogid=1000 rdev=00:00
obj=unconfined_u:object_r:user_home_t:s0 nametype=NORMAL
type=CWD msg=audit(1504310584.332:290): cwd="/home/sgrubb"
type=SYSCALL msg=audit(1504310584.332:290): arch=c000003e syscall=2
success=no exit=-1 a0=32cb3fca90 a1=0 a2=43 a3=8 items=1 ppid=901
pid=959 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000
fsuid=1000 egid=1000 sgid=1000 fsgid=1000 tty=pts1 ses=3 comm="bash"
exe="/usr/bin/bash" subj=unconfined_u:unconfined_r:unconfined_t:
s0-s0:c0.c1023 key=(null)
type=FANOTIFY msg=audit(1504310584.332:290): resp=2
Prior to using the audit flag, the developer needs to call
fanotify_init or'ing in FAN_ENABLE_AUDIT to ensure that the kernel
supports auditing. The calling process must also have the CAP_AUDIT_WRITE
capability.
Signed-off-by: sgrubb <sgrubb@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Pull ipc compat cleanup and 64-bit time_t from Al Viro:
"IPC copyin/copyout sanitizing, including 64bit time_t work from Deepa
Dinamani"
* 'work.ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
utimes: Make utimes y2038 safe
ipc: shm: Make shmid_kernel timestamps y2038 safe
ipc: sem: Make sem_array timestamps y2038 safe
ipc: msg: Make msg_queue timestamps y2038 safe
ipc: mqueue: Replace timespec with timespec64
ipc: Make sys_semtimedop() y2038 safe
get rid of SYSVIPC_COMPAT on ia64
semtimedop(): move compat to native
shmat(2): move compat to native
msgrcv(2), msgsnd(2): move compat to native
ipc(2): move compat to native
ipc: make use of compat ipc_perm helpers
semctl(): move compat to native
semctl(): separate all layout-dependent copyin/copyout
msgctl(): move compat to native
msgctl(): split the actual work from copyin/copyout
ipc: move compat shmctl to native
shmctl: split the work from copyin/copyout
Commit 2115bb250f ("audit: Use timespec64 to represent audit timestamps")
noted that audit timestamps were not y2038 safe and used a 64-bit
timestamp. In itself, this makes sense but the conversion was from
CURRENT_TIME to ktime_get_real_ts64() which is a heavier call to record
an accurate timestamp which is required in some, but not all, cases. The
impact is that when auditd is running without any rules that all syscalls
have higher overhead. This is visible in the sysbench-thread benchmark as
a 11.5% performance hit. That benchmark is dumb as rocks but it's also
visible in redis as an 8-10% hit on all operations which is of greater
concern. It is somewhat stupid of audit to track syscalls without any
rules related to syscalls but that is how it behaves.
The overhead can be directly measured with perf comparing 4.9 with 4.12
4.9
7.76% sysbench [kernel.vmlinux] [k] __schedule
7.62% sysbench [kernel.vmlinux] [k] _raw_spin_lock
7.37% sysbench libpthread-2.22.so [.] __lll_lock_elision
7.29% sysbench [kernel.vmlinux] [.] syscall_return_via_sysret
6.59% sysbench [kernel.vmlinux] [k] native_sched_clock
5.21% sysbench libc-2.22.so [.] __sched_yield
4.38% sysbench [kernel.vmlinux] [k] entry_SYSCALL_64
4.28% sysbench [kernel.vmlinux] [k] do_syscall_64
3.49% sysbench libpthread-2.22.so [.] __lll_unlock_elision
3.13% sysbench [kernel.vmlinux] [k] __audit_syscall_exit
2.87% sysbench [kernel.vmlinux] [k] update_curr
2.73% sysbench [kernel.vmlinux] [k] pick_next_task_fair
2.31% sysbench [kernel.vmlinux] [k] syscall_trace_enter
2.20% sysbench [kernel.vmlinux] [k] __audit_syscall_entry
.....
0.00% swapper [kernel.vmlinux] [k] read_tsc
4.12
7.84% sysbench [kernel.vmlinux] [k] __schedule
7.05% sysbench [kernel.vmlinux] [k] _raw_spin_lock
6.57% sysbench libpthread-2.22.so [.] __lll_lock_elision
6.50% sysbench [kernel.vmlinux] [.] syscall_return_via_sysret
5.95% sysbench [kernel.vmlinux] [k] read_tsc
5.71% sysbench [kernel.vmlinux] [k] native_sched_clock
4.78% sysbench libc-2.22.so [.] __sched_yield
4.30% sysbench [kernel.vmlinux] [k] entry_SYSCALL_64
3.94% sysbench [kernel.vmlinux] [k] do_syscall_64
3.37% sysbench libpthread-2.22.so [.] __lll_unlock_elision
3.32% sysbench [kernel.vmlinux] [k] __audit_syscall_exit
2.91% sysbench [kernel.vmlinux] [k] __getnstimeofday64
Note the additional overhead from read_tsc which goes from 0% to 5.95%.
This is on a single-socket E3-1230 but similar overheads have been measured
on an older machine which the patch also eliminates.
The patch in question has no explanation as to why a fully-accurate timestamp
is required and is likely an oversight. Using a coarser, but monotically
increasing, timestamp the overhead can be eliminated. While it can be
worked around by configuring or disabling audit, it's tricky enough to
detect that a kernel fix is justified. With this patch, we see the following;
sysbenchthread
4.9.0 4.12.0 4.12.0
vanilla vanilla coarse-v1r1
Amean 1 1.49 ( 0.00%) 1.66 ( -11.42%) 1.51 ( -1.34%)
Amean 3 1.48 ( 0.00%) 1.65 ( -11.45%) 1.50 ( -0.96%)
Amean 5 1.49 ( 0.00%) 1.67 ( -12.31%) 1.51 ( -1.83%)
Amean 7 1.49 ( 0.00%) 1.66 ( -11.72%) 1.50 ( -0.67%)
Amean 12 1.48 ( 0.00%) 1.65 ( -11.57%) 1.52 ( -2.89%)
Amean 16 1.49 ( 0.00%) 1.65 ( -11.13%) 1.51 ( -1.73%)
The benchmark is reporting the time required for different thread counts to
lock/unlock a private mutex which, while dense, demonstrates the syscall
overhead. This is showing that 4.12 took a 11-12% hit but the overhead is
almost eliminated by the patch. While the variance is not reported here,
it's well within the noise with the patch applied.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
struct timespec is not y2038 safe. Replace
all uses of timespec by y2038 safe struct timespec64.
Even though timespec is used here to represent timeouts,
replace these with timespec64 so that it facilitates
in verification by creating a y2038 safe kernel image
that is free of timespec.
The syscall interfaces themselves are not changed as part
of the patch. They will be part of a different series.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull audit updates from Paul Moore:
"Things are relatively quiet on the audit front for v4.13, just five
patches for a total diffstat of 102 lines.
There are two patches from Richard to consistently record the POSIX
capabilities and add the ambient capability information as well.
I also chipped in two patches to fix a race condition with the auditd
tracking code and ensure we don't skip sending any records to the
audit multicast group.
Finally a single style fix that I accepted because I must have been in
a good mood that day.
Everything passes our test suite, and should be relatively harmless,
please merge for v4.13"
* 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit:
audit: make sure we never skip the multicast broadcast
audit: fix a race condition with the auditd tracking code
audit: style fix
audit: add ambient capabilities to CAPSET and BPRM_FCAPS records
audit: unswing cap_* fields in PATH records
Capabilities were augmented to include ambient capabilities in v4.3
commit 58319057b7 ("capabilities: ambient capabilities").
Add ambient capabilities to the audit BPRM_FCAPS and CAPSET records.
The record contains fields "old_pp", "old_pi", "old_pe", "new_pp",
"new_pi", "new_pe" so in keeping with the previous record
normalizations, change the "new_*" variants to simply drop the "new_"
prefix.
A sample of the replaced BPRM_FCAPS record:
RAW: type=BPRM_FCAPS msg=audit(1491468034.252:237): fver=2
fp=0000000000200000 fi=0000000000000000 fe=1 old_pp=0000000000000000
old_pi=0000000000000000 old_pe=0000000000000000 old_pa=0000000000000000
pp=0000000000200000 pi=0000000000000000 pe=0000000000200000
pa=0000000000000000
INTERPRET: type=BPRM_FCAPS msg=audit(04/06/2017 04:40:34.252:237):
fver=2 fp=sys_admin fi=none fe=chown old_pp=none old_pi=none
old_pe=none old_pa=none pp=sys_admin pi=none pe=sys_admin pa=none
A sample of the replaced CAPSET record:
RAW: type=CAPSET msg=audit(1491469502.371:242): pid=833
cap_pi=0000003fffffffff cap_pp=0000003fffffffff cap_pe=0000003fffffffff
cap_pa=0000000000000000
INTERPRET: type=CAPSET msg=audit(04/06/2017 05:05:02.371:242) : pid=833
cap_pi=chown,dac_override,dac_read_search,fowner,fsetid,kill,
setgid,setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,sys_time,
sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pp=chown,dac_override,dac_read_search,fowner,fsetid,kill,setgid,
setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,
sys_time,sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pe=chown,dac_override,dac_read_search,fowner,fsetid,kill,setgid,
setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,
sys_time,sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pa=none
See: https://github.com/linux-audit/audit-kernel/issues/40
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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 5b52330bbf ("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
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
The audit event specification asks for certain fields to exist in
all events. Running 'ausearch -m anom_abend -sv yes' returns no
events. This patch adds the result field so that the
AUDIT_ANOM_ABEND event conforms to the rules.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Define AUDIT_SESSIONID in the uapi and add support for specifying user
filters based on the session ID. Also add the new session ID filter
to the feature bitmap so userspace knows it is available.
https://github.com/linux-audit/audit-kernel/issues/4
RFE: add a session ID filter to the kernel's user filter
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: combine multiple patches from Richard into this one]
Signed-off-by: Paul Moore <paul@paul-moore.com>
The value (unsigned int)-1 is used as a sentinel to indicate the
sessionID is unset. Skip this value when the session_id value wraps.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Tame initialization warning of len_abuf in audit_log_execve_info even
though there isn't presently a bug introduced by commit 43761473c2
("audit: fix a double fetch in audit_log_single_execve_arg()"). Using
UNINITIALIZED_VAR instead may mask future bugs.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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()
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>
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
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 <wpengfeinudt@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Fix the whitespace in the CWD record
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
[PM: fixed subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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
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>
Move the calculations of values after the allocation in case the
allocation fails. This avoids wasting effort in the rare case that it
fails, but more importantly saves us extra logic to release the tty
ref.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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
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>
Except on SPARC, this is what the code always did. SPARC compat seccomp
was buggy, although the impact of the bug was limited because SPARC
32-bit and 64-bit syscall numbers are the same.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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
This adds the ability audit the actions of a not-yet-running process.
This patch implements the ability to filter on the executable path. Instead of
just hard coding the ino and dev of the executable we care about at the moment
the rule is inserted into the kernel, use the new audit_fsnotify
infrastructure to manage this dynamically. This means that if the filename
does not yet exist but the containing directory does, or if the inode in
question is unlinked and creat'd (aka updated) the rule will just continue to
work. If the containing directory is moved or deleted or the filesystem is
unmounted, the rule is deleted automatically. A future enhancement would be to
have the rule survive across directory disruptions.
This is a heavily modified version of a patch originally submitted by Eric
Paris with some ideas from Peter Moody.
Cc: Peter Moody <peter@hda3.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: minor whitespace clean to satisfy ./scripts/checkpatch]
Signed-off-by: Paul Moore <pmoore@redhat.com>
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>
The "fix" in commit 0b08c5e594 ("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 <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Paul Moore <pmoore@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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
