linux.git/kernel/audit.c, branch v5.8-rc2

Merge tag 'audit-pr-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

2020-06-03T00:13:37+00:00

Pull audit updates from Paul Moore:
 "Summary of the significant patches:

   - Record information about binds/unbinds to the audit multicast
     socket. This helps identify which processes have/had access to the
     information in the audit stream.

   - Cleanup and add some additional information to the netfilter
     configuration events collected by audit.

   - Fix some of the audit error handling code so we don't leak network
     namespace references"

* tag 'audit-pr-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: add subj creds to NETFILTER_CFG record to
  audit: Replace zero-length array with flexible-array
  audit: make symbol 'audit_nfcfgs' static
  netfilter: add audit table unregister actions
  audit: tidy and extend netfilter_cfg x_tables
  audit: log audit netlink multicast bind and unbind
  audit: fix a net reference leak in audit_list_rules_send()
  audit: fix a net reference leak in audit_send_reply()

audit: log audit netlink multicast bind and unbind

2020-04-27T22:49:31+00:00

Log information about programs connecting to and disconnecting from the
audit netlink multicast socket. This is needed so that during
investigations a security officer can tell who or what had access to the
audit trail.  This helps to meet the FAU_SAR.2 requirement for Common
Criteria.

Here is the systemd startup event:
type=PROCTITLE msg=audit(2020-04-22 10:10:21.787:10) : proctitle=/init
type=SYSCALL msg=audit(2020-04-22 10:10:21.787:10) : arch=x86_64 syscall=bind success=yes exit=0 a0=0x19 a1=0x555f4aac7e90 a2=0xc a3=0x7ffcb792ff44 items=0 ppid=0 pid=1 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=systemd exe=/usr/lib/systemd/systemd subj=kernel key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 10:10:21.787:10) : pid=1 uid=root auid=unset tty=(none) ses=unset subj=kernel comm=systemd exe=/usr/lib/systemd/systemd nl-mcgrp=1 op=connect res=yes

And events from the test suite that just uses close():
type=PROCTITLE msg=audit(2020-04-22 11:47:08.501:442) : proctitle=/usr/bin/perl -w amcast_joinpart/test
type=SYSCALL msg=audit(2020-04-22 11:47:08.501:442) : arch=x86_64 syscall=bind success=yes exit=0 a0=0x7 a1=0x563004378760 a2=0xc a3=0x0 items=0 ppid=815 pid=818 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 11:47:08.501:442) : pid=818 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=connect res=yes

type=UNKNOWN[1335] msg=audit(2020-04-22 11:47:08.501:443) : pid=818 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=disconnect res=yes

And the events from the test suite using setsockopt with NETLINK_DROP_MEMBERSHIP:
type=PROCTITLE msg=audit(2020-04-22 11:39:53.291:439) : proctitle=/usr/bin/perl -w amcast_joinpart/test
type=SYSCALL msg=audit(2020-04-22 11:39:53.291:439) : arch=x86_64 syscall=bind success=yes exit=0 a0=0x7 a1=0x5560877c2d20 a2=0xc a3=0x0 items=0 ppid=772 pid=775 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 11:39:53.291:439) : pid=775 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=connect res=yes

type=PROCTITLE msg=audit(2020-04-22 11:39:53.292:440) : proctitle=/usr/bin/perl -w amcast_joinpart/test
type=SYSCALL msg=audit(2020-04-22 11:39:53.292:440) : arch=x86_64 syscall=setsockopt success=yes exit=0 a0=0x7 a1=SOL_NETLINK a2=0x2 a3=0x7ffc8366f000 items=0 ppid=772 pid=775 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 11:39:53.292:440) : pid=775 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=disconnect res=yes

Please see the upstream issue tracker at
  https://github.com/linux-audit/audit-kernel/issues/28
With the feature description at
  https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Multicast-Socket-Join-Part
The testsuite support is at
  https://github.com/rgbriggs/audit-testsuite/compare/ghak28-mcast-part-join
  https://github.com/linux-audit/audit-testsuite/pull/93
And the userspace support patch is at
  https://github.com/linux-audit/audit-userspace/pull/114

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: fix a net reference leak in audit_list_rules_send()

2020-04-22T19:23:10+00:00

If audit_list_rules_send() fails when trying to create a new thread
to send the rules it also fails to cleanup properly, leaking a
reference to a net structure.  This patch fixes the error patch and
renames audit_send_list() to audit_send_list_thread() to better
match its cousin, audit_send_reply_thread().

Reported-by: teroincn@gmail.com
Reviewed-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: fix a net reference leak in audit_send_reply()

2020-04-20T23:33:56+00:00

If audit_send_reply() fails when trying to create a new thread to
send the reply it also fails to cleanup properly, leaking a reference
to a net structure.  This patch fixes the error path and makes a
handful of other cleanups that came up while fixing the code.

Reported-by: teroincn@gmail.com
Reviewed-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: check the length of userspace generated audit records

2020-04-20T21:10:58+00:00

Commit 756125289285 ("audit: always check the netlink payload length
in audit_receive_msg()") fixed a number of missing message length
checks, but forgot to check the length of userspace generated audit
records.  The good news is that you need CAP_AUDIT_WRITE to submit
userspace audit records, which is generally only given to trusted
processes, so the impact should be limited.

Cc: stable@vger.kernel.org
Fixes: 756125289285 ("audit: always check the netlink payload length in audit_receive_msg()")
Reported-by: syzbot+49e69b4d71a420ceda3e@syzkaller.appspotmail.com
Signed-off-by: Paul Moore

Merge tag 'audit-pr-20200330' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

2020-03-31T22:04:17+00:00

Pull audit updates from Paul Moore:
 "We've got two audit patches for the v5.7 merge window with a stellar
  14 lines changed between the two patches. The patch descriptions are
  far more lengthy than the patches themselves, which is a very good
  thing for patches this size IMHO. The patches pass our test suites and
  a quick summary is below:

   - Stop logging inode information when updating an audit file watch.

     Since we are not changing the inode, or the fact that we are
     watching the associated file, the inode information is just noise
     that we can do without.

   - Fix a problem where mandatory audit records were missing their
     accompanying audit records (e.g. SYSCALL records were missing).

     The missing records often meant that we didn't have the necessary
     context to understand what was going on when the event occurred"

* tag 'audit-pr-20200330' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: trigger accompanying records when no rules present
  audit: CONFIG_CHANGE don't log internal bookkeeping as an event

audit: trigger accompanying records when no rules present

2020-03-12T14:42:51+00:00

When there are no audit rules registered, mandatory records (config,
etc.) are missing their accompanying records (syscall, proctitle, etc.).

This is due to audit context dummy set on syscall entry based on absence
of rules that signals that no other records are to be printed.

Clear the dummy bit if any record is generated.

The proctitle context and dummy checks are pointless since the
proctitle record will not be printed if no syscall records are printed.

Please see upstream github issue
https://github.com/linux-audit/audit-kernel/issues/120

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: always check the netlink payload length in audit_receive_msg()

2020-02-24T21:38:57+00:00

This patch ensures that we always check the netlink payload length
in audit_receive_msg() before we take any action on the payload
itself.

Cc: stable@vger.kernel.org
Reported-by: syzbot+399c44bf1f43b8747403@syzkaller.appspotmail.com
Reported-by: syzbot+e4b12d8d202701f08b6d@syzkaller.appspotmail.com
Signed-off-by: Paul Moore

audit: Add __rcu annotation to RCU pointer

2019-12-09T20:19:03+00:00

Add __rcu annotation to RCU-protected global pointer auditd_conn.

auditd_conn is an RCU-protected global pointer,i.e., accessed
via RCU methods rcu_dereference() and rcu_assign_pointer(),
hence it must be annotated with __rcu for sparse to report
warnings/errors correctly.

Fix multiple instances of the sparse error:
error: incompatible types in comparison expression
(different address spaces)

Reviewed-by: Joel Fernandes (Google) 
Signed-off-by: Amol Grover 
[PM: tweak subject line]
Signed-off-by: Paul Moore

audit: remove redundant condition check in kauditd_thread()

2019-10-25T15:48:14+00:00

Warning is found by the code analysis tool:
  "the condition 'if(ac && rc < 0)' is redundant: ac"

The @ac variable has been checked before. It can't be a null pointer
here, so remove the redundant condition check.

Signed-off-by: Yunfeng Ye 
Signed-off-by: Paul Moore