Re: [PATCH 1/1] audit,io_uring,io-wq: call __audit_uring_exit for dummy contexts

[Paul Moore]

On Tue, May 17, 2022 at 9:12 AM Paul Moore <paul@xxxxxxxxxxxxxx> wrote:
> On Tue, May 17, 2022 at 6:33 AM Julian Orth <ju.orth@xxxxxxxxx> wrote:
> >
> > Not calling the function for dummy contexts will cause the context to
> > not be reset. During the next syscall, this will cause an error in
> > __audit_syscall_entry:
> >
> >         WARN_ON(context->context != AUDIT_CTX_UNUSED);
> >         WARN_ON(context->name_count);
> >         if (context->context != AUDIT_CTX_UNUSED || context->name_count) {
> >                 audit_panic("unrecoverable error in audit_syscall_entry()");
> >                 return;
> >         }
> >
> > These problematic dummy contexts are created via the following call
> > chain:
> >
> >        exit_to_user_mode_prepare
> >     -> arch_do_signal_or_restart
> >     -> get_signal
> >     -> task_work_run
> >     -> tctx_task_work
> >     -> io_req_task_submit
> >     -> io_issue_sqe
> >     -> audit_uring_entry
> >
> > Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
> > Signed-off-by: Julian Orth <ju.orth@xxxxxxxxx>
> > ---
> >  include/linux/audit.h | 2 +-
> >  kernel/auditsc.c      | 6 ++++++
> >  2 files changed, 7 insertions(+), 1 deletion(-)
>
> Hi Julian,
>
> Thanks for the report and the patch too!  I agree that it does seem a
> little odd that we haven't seen this before, let me dig into this a
> bit more today and respond back.

The patch looks good to me, thanks again.  I just merged this into the
audit/stable-5.18 branch and added a stable tag; assuming the test
runs go okay I'll send this up to Linus tomorrow.

-- 
paul-moore.com