Re: [PATCH] audit: add arch field to seccomp event log

[Eric Paris <eparis@redhat.com>]

On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> The AUDIT_SECCOMP record looks something like this:
> 
> type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
> 
> In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
> 
> To see the event, compile this test.c program:
> 
> =====
> int main(void)
> {
>         return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> }
> =====
> 
> gcc -g test.c -o test -lseccomp
> 
> After running the program, find the record by:  ausearch --start recent -m SECCOMP -i
> ---
>  kernel/auditsc.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 6874c1f..c464d44 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
>  		return;
>  	audit_log_task(ab);
>  	audit_log_format(ab, " sig=%ld", signr);
> +	audit_log_format(ab, " arch=%x", current->audit_context->arch);


What happens if the task does not have current->audit_context allocated?
Seems possible if signr is non-zero...


>  	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));