Whenever there's audit context, __audit_inode_child() gets called
numerous times, which can lead to high latency in scenarios that
create too many sysfs/debugfs entries at once, for instance, upon
device_add_disk() invocation.

   # uname -r
   6.18.0-rc2+

   # auditctl -a always,exit -F path=/tmp -k foo
   # time insmod loop max_loop=1000
   real 0m46.676s
   user 0m0.000s
   sys 0m46.405s

   # perf record -a insmod loop max_loop=1000
   # perf report --stdio |grep __audit_inode_child
   32.73%  insmod [kernel.kallsyms] [k] __audit_inode_child

__audit_inode_child() searches for both the parent and the child
in two different loops that iterate over the same list. This
process can be optimized by merging these into a single loop,
without changing the function behavior or affecting the code's
readability.

This patch merges the two loops that walk through the list
context->names_list into a single loop. This optimization resulted
in around 51% performance enhancement for the benchmark.

   # uname -r
   6.18.0-rc2-enhancedv3+

   # auditctl -a always,exit -F path=/tmp -k foo
   # time insmod loop max_loop=1000
   real 0m22.899s
   user 0m0.001s
   sys 0m22.652s

Signed-off-by: Ricardo Robaina <rrobaina@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Create a new audit record AUDIT_MAC_OBJ_CONTEXTS.
An example of the MAC_OBJ_CONTEXTS record is:

    type=MAC_OBJ_CONTEXTS
      msg=audit(1601152467.009:1050):
      obj_selinux=unconfined_u:object_r:user_home_t:s0

When an audit event includes a AUDIT_MAC_OBJ_CONTEXTS record
the "obj=" field in other records in the event will be "obj=?".
An AUDIT_MAC_OBJ_CONTEXTS record is supplied when the system has
multiple security modules that may make access decisions based
on an object security context.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj tweak, audit example readability indents]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Add a parameter lsmid to security_lsmblob_to_secctx() to identify which
of the security modules that may be active should provide the security
context. If the value of lsmid is LSM_ID_UNDEF the first LSM providing
a hook is used. security_secid_to_secctx() is unchanged, and will
always report the first LSM providing a hook.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Replace the timestamp and serial number pair used in audit records
with a structure containing the two elements.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Someone got a bit carried away deleting tabs.  Add it back.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Fix two indentation errors in audit_log_exit().

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>

The move of the module sanity check to earlier skipped the audit logging
call in the case of failure and to a place where the previously used
context is unavailable.

Add an audit logging call for the module loading failure case and get
the module name when possible.

Link: https://issues.redhat.com/browse/RHEL-52839
Fixes: 02da2cbab452 ("module: move check_modinfo() early to early_mod_check()")
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

No functional changes.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250313142744.1323281-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

Pull lsm updates from Paul Moore:

 - Improved handling of LSM "secctx" strings through lsm_context struct

   The LSM secctx string interface is from an older time when only one
   LSM was supported, migrate over to the lsm_context struct to better
   support the different LSMs we now have and make it easier to support
   new LSMs in the future.

   These changes explain the Rust, VFS, and networking changes in the
   diffstat.

 - Only build lsm_audit.c if CONFIG_SECURITY and CONFIG_AUDIT are
   enabled

   Small tweak to be a bit smarter about when we build the LSM's common
   audit helpers.

 - Check for absurdly large policies from userspace in SafeSetID

   SafeSetID policies rules are fairly small, basically just "UID:UID",
   it easy to impose a limit of KMALLOC_MAX_SIZE on policy writes which
   helps quiet a number of syzbot related issues. While work is being
   done to address the syzbot issues through other mechanisms, this is a
   trivial and relatively safe fix that we can do now.

 - Various minor improvements and cleanups

   A collection of improvements to the kernel selftests, constification
   of some function parameters, removing redundant assignments, and
   local variable renames to improve readability.

* tag 'lsm-pr-20250121' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  lockdown: initialize local array before use to quiet static analysis
  safesetid: check size of policy writes
  net: corrections for security_secid_to_secctx returns
  lsm: rename variable to avoid shadowing
  lsm: constify function parameters
  security: remove redundant assignment to return variable
  lsm: Only build lsm_audit.c if CONFIG_SECURITY and CONFIG_AUDIT are set
  selftests: refactor the lsm `flags_overset_lsm_set_self_attr` test
  binder: initialize lsm_context structure
  rust: replace lsm context+len with lsm_context
  lsm: secctx provider check on release
  lsm: lsm_context in security_dentry_init_security
  lsm: use lsm_context in security_inode_getsecctx
  lsm: replace context+len with lsm_context
  lsm: ensure the correct LSM context releaser

A build failure has been reported with the following details:

   In file included from include/linux/string.h:390,
                    from include/linux/bitmap.h:13,
                    from include/linux/cpumask.h:12,
                    from include/linux/smp.h:13,
                    from include/linux/lockdep.h:14,
                    from include/linux/spinlock.h:63,
                    from include/linux/wait.h:9,
                    from include/linux/wait_bit.h:8,
                    from include/linux/fs.h:6,
                    from kernel/auditsc.c:37:
   In function 'sized_strscpy',
       inlined from '__audit_ptrace' at kernel/auditsc.c:2732:2:
>> include/linux/fortify-string.h:293:17:
   error: call to '__write_overflow' declared with attribute error:
   detected write beyond size of object (1st parameter)
     293 |                 __write_overflow();
         |                 ^~~~~~~~~~~~~~~~~~
   In function 'sized_strscpy',
       inlined from 'audit_signal_info_syscall' at kernel/auditsc.c:2759:3:
>> include/linux/fortify-string.h:293:17:
   error: call to '__write_overflow' declared with attribute error:
   detected write beyond size of object (1st parameter)
     293 |                 __write_overflow();
         |                 ^~~~~~~~~~~~~~~~~~

The issue appears to be a GCC bug, though the root cause remains
unclear at this time. For now, let's implement a workaround.

A bug report has also been filed with GCC [0].

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117912 [0]

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410171420.1V00ICVG-lkp@intel.com/
Reported-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Closes: https://lore.kernel.org/all/20241128182435.57a1ea6f@gandalf.local.home/
Reported-by: Zhuo, Qiuxu <qiuxu.zhuo@intel.com>
Closes: https://lore.kernel.org/all/CY8PR11MB71348E568DBDA576F17DAFF389362@CY8PR11MB7134.namprd11.prod.outlook.com/
Originally-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/linux-hardening/202410171059.C2C395030@keescook/
Signed-off-by: Yafang shao <laoar.shao@gmail.com>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Yafang Shao <laoar.shao@gmail.com>
[PM: subject tweak, description line wrapping]
Signed-off-by: Paul Moore <paul@paul-moore.com>