| From cdee3904b4ce7c03d1013ed6dd704b43ae7fc2e9 Mon Sep 17 00:00:00 2001 |
| From: Anton Blanchard <anton@samba.org> |
| Date: Wed, 9 Jan 2013 10:46:17 +1100 |
| Subject: audit: Syscall rules are not applied to existing processes on non-x86 |
| |
| From: Anton Blanchard <anton@samba.org> |
| |
| commit cdee3904b4ce7c03d1013ed6dd704b43ae7fc2e9 upstream. |
| |
| 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> |
| Signed-off-by: Eric Paris <eparis@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| include/linux/audit.h | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/include/linux/audit.h |
| +++ b/include/linux/audit.h |
| @@ -120,7 +120,7 @@ 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) |
