From 9a29d0fbc2d9ad99fb8a981ab72548cc360e9d4c Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 14 Dec 2016 15:05:38 -0800 Subject: [PATCH] relay: check array offset before using it Smatch complains that we started using the array offset before we checked that it was valid. Fixes: 017c59c042d0 ('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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/relay.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/relay.c b/kernel/relay.c index da79a109dbeb..8f18d314a96a 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -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) -- 2.39.5