<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/audit.h, branch v4.16-rc6</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'audit-pr-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit</title>
<updated>2017-11-15T21:28:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-15T21:28:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f9bab2677ac77622618686b199073978ba263c12'/>
<id>f9bab2677ac77622618686b199073978ba263c12</id>
<content type='text'>
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
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: convert audit_ever_enabled to a boolean</title>
<updated>2017-11-10T21:07:54+00:00</updated>
<author>
<name>Paul Moore</name>
<email>paul@paul-moore.com</email>
</author>
<published>2017-09-01T13:44:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b3b4fdf6a8ae9ea51ea274e3f2f8a6a58b98cc0b'/>
<id>b3b4fdf6a8ae9ea51ea274e3f2f8a6a58b98cc0b</id>
<content type='text'>
We were treating it as a boolean, let's make it a boolean to help
avoid future mistakes.

Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We were treating it as a boolean, let's make it a boolean to help
avoid future mistakes.

Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipc: mqueue: Replace timespec with timespec64</title>
<updated>2017-09-04T00:21:24+00:00</updated>
<author>
<name>Deepa Dinamani</name>
<email>deepa.kernel@gmail.com</email>
</author>
<published>2017-08-03T02:51:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b9047726386bb538cf5e4f52a9f04eb556eebc67'/>
<id>b9047726386bb538cf5e4f52a9f04eb556eebc67</id>
<content type='text'>
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 &lt;deepa.kernel@gmail.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;deepa.kernel@gmail.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: style fix</title>
<updated>2017-06-12T22:07:43+00:00</updated>
<author>
<name>Derek Robson</name>
<email>robsonde@gmail.com</email>
</author>
<published>2017-06-12T02:33:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e4c1a0d15b62a3ed2f8cd560e9fa589dbe880c13'/>
<id>e4c1a0d15b62a3ed2f8cd560e9fa589dbe880c13</id>
<content type='text'>
Fixed checkpatch.pl warnings of "function definition argument FOO
should also have an identifier name"

Signed-off-by: Derek Robson &lt;robsonde@gmail.com&gt;
Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixed checkpatch.pl warnings of "function definition argument FOO
should also have an identifier name"

Signed-off-by: Derek Robson &lt;robsonde@gmail.com&gt;
Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: add ambient capabilities to CAPSET and BPRM_FCAPS records</title>
<updated>2017-05-30T21:36:11+00:00</updated>
<author>
<name>Richard Guy Briggs</name>
<email>rgb@redhat.com</email>
</author>
<published>2017-04-07T14:17:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7786f6b6dfc12d17eea2df04116de6ebac50c884'/>
<id>7786f6b6dfc12d17eea2df04116de6ebac50c884</id>
<content type='text'>
Capabilities were augmented to include ambient capabilities in v4.3
commit 58319057b784 ("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 &lt;rgb@redhat.com&gt;
Acked-by: Serge Hallyn &lt;serge@hallyn.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Capabilities were augmented to include ambient capabilities in v4.3
commit 58319057b784 ("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 &lt;rgb@redhat.com&gt;
Acked-by: Serge Hallyn &lt;serge@hallyn.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: Use timespec64 to represent audit timestamps</title>
<updated>2017-05-02T14:16:05+00:00</updated>
<author>
<name>Deepa Dinamani</name>
<email>deepa.kernel@gmail.com</email>
</author>
<published>2017-05-02T14:16:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2115bb250f260089743e26decfb5f271ba71ca37'/>
<id>2115bb250f260089743e26decfb5f271ba71ca37</id>
<content type='text'>
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 &lt;deepa.kernel@gmail.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Acked-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;deepa.kernel@gmail.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Acked-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: store the auditd PID as a pid struct instead of pid_t</title>
<updated>2017-05-02T14:16:05+00:00</updated>
<author>
<name>Paul Moore</name>
<email>paul@paul-moore.com</email>
</author>
<published>2017-05-02T14:16:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b6c7c115c2ce679ac536f0adf0ff518fcd939196'/>
<id>b6c7c115c2ce679ac536f0adf0ff518fcd939196</id>
<content type='text'>
This is arguably the right thing to do, and will make it easier when
we start supporting multiple audit daemons in different namespaces.

Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is arguably the right thing to do, and will make it easier when
we start supporting multiple audit daemons in different namespaces.

Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: kernel generated netlink traffic should have a portid of 0</title>
<updated>2017-05-02T14:16:05+00:00</updated>
<author>
<name>Paul Moore</name>
<email>paul@paul-moore.com</email>
</author>
<published>2017-05-02T14:16:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=45a0642b4d021a2f50d5db9c191b5bfe60bfa1c7'/>
<id>45a0642b4d021a2f50d5db9c191b5bfe60bfa1c7</id>
<content type='text'>
We were setting the portid incorrectly in the netlink message headers,
fix that to always be 0 (nlmsg_pid = 0).

Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We were setting the portid incorrectly in the netlink message headers,
fix that to always be 0 (nlmsg_pid = 0).

Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Reviewed-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: move audit_signal_info() into kernel/auditsc.c</title>
<updated>2017-03-27T18:30:06+00:00</updated>
<author>
<name>Paul Moore</name>
<email>paul@paul-moore.com</email>
</author>
<published>2017-03-27T18:30:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ab6434a1377a768a1e6d3e6cf819eb21724a99c2'/>
<id>ab6434a1377a768a1e6d3e6cf819eb21724a99c2</id>
<content type='text'>
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 &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: fix auditd/kernel connection state tracking</title>
<updated>2017-03-21T15:26:35+00:00</updated>
<author>
<name>Paul Moore</name>
<email>paul@paul-moore.com</email>
</author>
<published>2017-03-21T15:26:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5b52330bbfe63b3305765354d6046c9f7f89c011'/>
<id>5b52330bbfe63b3305765354d6046c9f7f89c011</id>
<content type='text'>
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: &lt;stable@vger.kernel.org&gt; # 4.10.x-
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
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<pre>
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: &lt;stable@vger.kernel.org&gt; # 4.10.x-
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
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