Unfortunately the commit listed in the subject line above failed
to ensure that the task's audit_context was properly initialized/set
before enabling the "accompanying records". Depending on the
sitation, the resulting audit_context could have invalid values in
some of it's fields which could cause a kernel panic/oops when the
task/syscall exists and the audit records are generated.
We will revisit the original patch, with the necessary fixes, in a
future kernel but right now we just want to fix the kernel panic
with the least amount of added risk.
Cc: stable(a)vger.kernel.org
Fixes: 1320a4052ea1 ("audit: trigger accompanying records when no rules
present")
Reported-by: j2468h(a)googlemail.com
Signed-off-by: Paul Moore <paul(a)paul-moore.com>
---
kernel/audit.c | 1 -
kernel/audit.h | 8 --------
kernel/auditsc.c | 3 +++
3 files changed, 3 insertions(+), 9 deletions(-)
diff --git a/kernel/audit.c b/kernel/audit.c
index e33460e01b3b..9bf2b08b051f 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1848,7 +1848,6 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx,
gfp_t gfp_mask,
}
audit_get_stamp(ab->ctx, &t, &serial);
- audit_clear_dummy(ab->ctx);
audit_log_format(ab, "audit(%llu.%03lu:%u): ",
(unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
diff --git a/kernel/audit.h b/kernel/audit.h
index f0233dc40b17..ddc22878433d 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -290,13 +290,6 @@ extern int audit_signal_info_syscall(struct task_struct *t);
extern void audit_filter_inodes(struct task_struct *tsk,
struct audit_context *ctx);
extern struct list_head *audit_killed_trees(void);
-
-static inline void audit_clear_dummy(struct audit_context *ctx)
-{
- if (ctx)
- ctx->dummy = 0;
-}
-
#else /* CONFIG_AUDITSYSCALL */
#define auditsc_get_stamp(c, t, s) 0
#define audit_put_watch(w) {}
@@ -330,7 +323,6 @@ static inline int audit_signal_info_syscall(struct task_struct *t)
}
#define audit_filter_inodes(t, c) AUDIT_DISABLED
-#define audit_clear_dummy(c) {}
#endif /* CONFIG_AUDITSYSCALL */
extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 468a23390457..fd840c40abf7 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1417,6 +1417,9 @@ static void audit_log_proctitle(void)
struct audit_context *context = audit_context();
struct audit_buffer *ab;
+ if (!context || context->dummy)
+ return;
+
ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
if (!ab)
return; /* audit_panic or being filtered */