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

On 14/02/14, Richard Guy Briggs wrote: > On 14/02/14, Eric Paris wrote: > > 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... > > I had assumed that since we got this far, that there was an audit > context. This was my first patch: Sorry, pulled the trigger too fast: --- kernel/auditsc.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 6874c1f..3023d03 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr) void __audit_seccomp(unsigned long syscall, long signr, int code) { struct audit_buffer *ab; + struct audit_context *context audit_get_context(current, 0, 0);

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, " arch="); + if (context) + audit_log_format(ab, "(null)"); + else + audit_log_format(ab, "%x", context->arch); 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));