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>

diff --git a/include/linux/audit.h b/include/linux/audit.h
index bce729a..9d5104d 100644 (file)
--- 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);
 }
 

diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 76352ac..09a2d94 100644 (file)
--- 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 */

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index e37e6a1..3e46d1d 100644 (file)
--- 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));