On Thu, Sep 03, 2026 at 01:27:28PM -0400, Steven Rostedt wrote: > From: Steven Rostedt <[email protected]> > > Sashiko reported that the code was using meta->nr_subbufs without making > sure that it matched the nr_pages + 1 on data that was assuming the two > were the same. > > Add a check to the persistent ring buffer validation code to make sure > that the saved nr_subbufs matches what we expect. > > Fixes: f5b95f1fa2ef3 ("ring-buffer: Validate the persistent meta data subbuf > array") > Reported-by: [email protected] > Closes: > https://lore.kernel.org/all/[email protected]/ > Signed-off-by: Steven Rostedt <[email protected]>
Reviewed-by: Vincent Donnefort <[email protected]> > --- > kernel/trace/ring_buffer.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index ef66f726e2e2..748d4ae8badf 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -1869,6 +1869,11 @@ static bool rb_cpu_meta_valid(struct > ring_buffer_cpu_meta *meta, int cpu, > return false; > } > > + if (meta->nr_subbufs != nr_pages + 1) { > + pr_info("Ring buffer boot meta [%d] invalid nr_subbufs\n", cpu); > + return false; > + } > + > buffers_start = meta->first_buffer; > buffers_end = meta->first_buffer + (subbuf_size * meta->nr_subbufs); > > -- > 2.53.0 >
