audit: create explicit AUDIT_SECCOMP event type

The seccomp path was using AUDIT_ANOM_ABEND from when seccomp mode 1
could only kill a process.  While we still want to make sure an audit
record is forced on a kill, this should use a separate record type since
seccomp mode 2 introduces other behaviors.

In the case of "handled" behaviors (process wasn't killed), only emit a
record if the process is under inspection.  This change also fixes
userspace examination of seccomp audit events, since it was considered
malformed due to missing fields of the AUDIT_ANOM_ABEND event type.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Julien Tinnes <jln@google.com>
Acked-by: Will Drewry <wad@chromium.org>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 3 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index e37e6a12c5e3..3e46d1dec613 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2675,7 +2675,7 @@ void __audit_mmap_fd(int fd, int flags)
         context->type = AUDIT_MMAP;
 }
 
-static void audit_log_abend(struct audit_buffer *ab, char *reason, long signr)
+static void audit_log_task(struct audit_buffer *ab)
 {
         kuid_t auid, uid;
         kgid_t gid;
@@ -2693,6 +2693,11 @@ static void audit_log_abend(struct audit_buffer *ab, char *reason, long signr)
         audit_log_task_context(ab);
         audit_log_format(ab, " pid=%d comm=", current->pid);
         audit_log_untrustedstring(ab, current->comm);
+}
+
+static void audit_log_abend(struct audit_buffer *ab, char *reason, long signr)
+{
+        audit_log_task(ab);
         audit_log_format(ab, " reason=");
         audit_log_string(ab, reason);
         audit_log_format(ab, " sig=%ld", signr);
@@ -2723,8 +2728,11 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
 {
         struct audit_buffer *ab;
 
-        ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
-        audit_log_abend(ab, "seccomp", signr);
+        ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
+        if (unlikely(!ab))
+                return;
+        audit_log_task(ab);
+        audit_log_format(ab, " sig=%ld", signr);
         audit_log_format(ab, " syscall=%ld", syscall);
         audit_log_format(ab, " compat=%d", is_compat_task());
         audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));