[PATCH] fix broken timestamps in AVC generated by kernel threads

Timestamp in audit_context is valid only if ->in_syscall is set.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 7 insertions, 6 deletions

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 1b2a6a5c1876..8f0672d13eb1 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -435,7 +435,7 @@ static inline void audit_ptrace(struct task_struct *t)
 
                                 /* Private API (for audit.c only) */
 extern unsigned int audit_serial(void);
-extern void auditsc_get_stamp(struct audit_context *ctx,
+extern int auditsc_get_stamp(struct audit_context *ctx,
                               struct timespec *t, unsigned int *serial);
 extern int  audit_set_loginuid(struct task_struct *task, uid_t loginuid);
 #define audit_get_loginuid(t) ((t)->loginuid)
@@ -518,7 +518,7 @@ extern int audit_signals;
 #define audit_inode(n,d) do { ; } while (0)
 #define audit_inode_child(d,i,p) do { ; } while (0)
 #define audit_core_dumps(i) do { ; } while (0)
-#define auditsc_get_stamp(c,t,s) do { BUG(); } while (0)
+#define auditsc_get_stamp(c,t,s) (0)
 #define audit_get_loginuid(t) (-1)
 #define audit_get_sessionid(t) (-1)
 #define audit_log_task_context(b) do { ; } while (0)
diff --git a/kernel/audit.c b/kernel/audit.c
index d8646c23b427..ce6d8ea3131e 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1121,9 +1121,7 @@ unsigned int audit_serial(void)
 static inline void audit_get_stamp(struct audit_context *ctx,
                                    struct timespec *t, unsigned int *serial)
 {
-        if (ctx)
-                auditsc_get_stamp(ctx, t, serial);
-        else {
+        if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
                 *t = CURRENT_TIME;
                 *serial = audit_serial();
         }
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 0a13d6895494..2a3f0afc4d2a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1957,15 +1957,18 @@ EXPORT_SYMBOL_GPL(__audit_inode_child);
  *
  * Also sets the context as auditable.
  */
-void auditsc_get_stamp(struct audit_context *ctx,
+int auditsc_get_stamp(struct audit_context *ctx,
                        struct timespec *t, unsigned int *serial)
 {
+        if (!ctx->in_syscall)
+                return 0;
         if (!ctx->serial)
                 ctx->serial = audit_serial();
         t->tv_sec  = ctx->ctime.tv_sec;
         t->tv_nsec = ctx->ctime.tv_nsec;
         *serial    = ctx->serial;
         ctx->auditable = 1;
+        return 1;
 }
 
 /* global counter which is incremented every time something logs in */