Messages in this thread Patch in this message |  | | Date | Wed, 9 Jan 2013 10:46:17 +1100 | From | Anton Blanchard <> | Subject | [PATCH 1/4] audit: Syscall rules are not applied to existing processes on non-x86 |
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Commit b05d8447e782 (audit: inline audit_syscall_entry to reduce burden on archs) changed audit_syscall_entry to check for a dummy context before calling __audit_syscall_entry. Unfortunately the dummy context state is maintained in __audit_syscall_entry so once set it never gets cleared, even if the audit rules change.
As a result, if there are no auditing rules when a process starts then it will never be subject to any rules added later. x86 doesn't see this because it has an assembly fast path that calls directly into __audit_syscall_entry.
I noticed this issue when working on audit performance optimisations. I wrote a set of simple test cases available at:
http://ozlabs.org/~anton/junkcode/audit_tests.tar.gz
02_new_rule.py fails without the patch and passes with it. The test case clears all rules, starts a process, adds a rule then verifies the process produces a syscall audit record.
Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> # 3.3+ ---
Index: b/include/linux/audit.h =================================================================== --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -119,7 +119,7 @@ static inline void audit_syscall_entry(i unsigned long a1, unsigned long a2, unsigned long a3) { - if (unlikely(!audit_dummy_context())) + if (unlikely(current->audit_context)) __audit_syscall_entry(arch, major, a0, a1, a2, a3); } static inline void audit_syscall_exit(void *pt_regs)
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