Re: [PATCH bpf-next] bpf: Lock bpf_trace_printk's tmp buf before it is written to

From: Alexei Starovoitov
Date: Tue Apr 27 2021 - 11:24:03 EST


On Tue, Apr 27, 2021 at 8:20 AM Florent Revest <revest@xxxxxxxxxxxx> wrote:
>
> On Tue, Apr 27, 2021 at 5:08 PM Alexei Starovoitov
> <alexei.starovoitov@xxxxxxxxx> wrote:
> >
> > On Tue, Apr 27, 2021 at 4:30 AM Florent Revest <revest@xxxxxxxxxxxx> wrote:
> > >
> > > bpf_trace_printk uses a shared static buffer to hold strings before they
> > > are printed. A recent refactoring moved the locking of that buffer after
> > > it gets filled by mistake.
> > >
> > > Fixes: d9c9e4db186a ("bpf: Factorize bpf_trace_printk and bpf_seq_printf")
> > > Reported-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> > > Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
> >
> > Applied.
>
> Thanks!
>
> > Pls send v2 of bstr_printf series as soon as possible. Thanks!
>
> Sure, I just assumed there would be more reviews on v1. The feedback
> I'll address is only about the commit description wording but I can
> send a v2 today.

Yes. Please.