[ 102/221] audit: create explicit AUDIT_SECCOMP event type

Greg Kroah-Hartman
2013-01-15T22:31:42Z

From: Kees Cook <keescook@chromium.org>

commit 7b9205bd775afc4439ed86d617f9042ee9e76a71 upstream.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/linux/audit.h | 3 ++-
include/uapi/linux/audit.h | 1 +
kernel/auditsc.c | 14 +++++++++++---
3 files changed, 14 insertions(+), 4 deletions(-)

--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -157,7 +157,8 @@ void audit_core_dumps(long signr);

static inline void audit_seccomp(unsigned long syscall, long signr, int code)
{
- if (unlikely(!audit_dummy_context()))
+ /* Force a record to be reported if a signal was delivered. */
+ if (signr || unlikely(!audit_dummy_context()))
__audit_seccomp(syscall, signr, code);
}

--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -106,6 +106,7 @@
#define AUDIT_MMAP 1323 /* Record showing descriptor and flags in mmap */
#define AUDIT_NETFILTER_PKT 1324 /* Packets traversing netfilter chains */
#define AUDIT_NETFILTER_CFG 1325 /* Netfilter chain modifications */
+#define AUDIT_SECCOMP 1326 /* Secure Computing event */

#define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
#define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2735,7 +2735,7 @@ 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;
@@ -2753,6 +2753,11 @@ static void audit_log_abend(struct audit
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);
@@ -2783,8 +2788,11 @@ void __audit_seccomp(unsigned long sysca
{
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));