Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 6.1 43/52] block: prevent division by zero in blk_rq_stat_sum() | Date | Fri, 29 Mar 2024 08:45:37 -0400 |
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From: Roman Smirnov <r.smirnov@omp.ru>
[ Upstream commit 93f52fbeaf4b676b21acfe42a5152620e6770d02 ]
The expression dst->nr_samples + src->nr_samples may have zero value on overflow. It is necessary to add a check to avoid division by zero.
Found by Linux Verification Center (linuxtesting.org) with Svace.
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru> Link: https://lore.kernel.org/r/20240305134509.23108-1-r.smirnov@omp.ru Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> --- block/blk-stat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-stat.c b/block/blk-stat.c index da9407b7d4abf..41be89ecaf20e 100644 --- a/block/blk-stat.c +++ b/block/blk-stat.c @@ -28,7 +28,7 @@ void blk_rq_stat_init(struct blk_rq_stat *stat) /* src is a per-cpu stat, mean isn't initialized */ void blk_rq_stat_sum(struct blk_rq_stat *dst, struct blk_rq_stat *src) { - if (!src->nr_samples) + if (dst->nr_samples + src->nr_samples <= dst->nr_samples) return; dst->min = min(dst->min, src->min); -- 2.43.0
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