From cdee3904b4ce7c03d1013ed6dd704b43ae7fc2e9 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 9 Jan 2013 10:46:17 +1100 Subject: [PATCH] audit: Syscall rules are not applied to existing processes on non-x86 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 Cc: # 3.3+ Signed-off-by: Eric Paris --- include/linux/audit.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 5a6d718..37464c5 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -120,7 +120,7 @@ static inline void audit_syscall_entry(int arch, int major, unsigned long a0, 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) -- 2.7.4