relay: check array offset before using it

Smatch complains that we started using the array offset before we
checked that it was valid.

Fixes: 017c59c042 ('relay: Use per CPU constructs for the relay channel buffer pointers')
Link: http://lkml.kernel.org/r/20161013084947.GC16198@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dan Carpenter 2016-12-14 15:05:38 -08:00 committed by Linus Torvalds
parent bd4171a5d4
commit 9a29d0fbc2

View File

@ -809,11 +809,11 @@ void relay_subbufs_consumed(struct rchan *chan,
{
struct rchan_buf *buf;
if (!chan)
if (!chan || cpu >= NR_CPUS)
return;
buf = *per_cpu_ptr(chan->buf, cpu);
if (cpu >= NR_CPUS || !buf || subbufs_consumed > chan->n_subbufs)
if (!buf || subbufs_consumed > chan->n_subbufs)
return;
if (subbufs_consumed > buf->subbufs_produced - buf->subbufs_consumed)