From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3013A5D73A; Sun, 24 Mar 2024 17:07:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711300053; cv=none; b=kiCZyfdV1WMLaHTWg+db6fOUfYk5p0IyUjJfJ9kQiOhS3T7z8yxg9H9vqvQFqx28WtmYf7FKKSXWRt7gSZZvVUBa3v3BF78Tdv59egIKZpCCaV7e3zK3qy2jEktMdKxg77UDsE9ugijwBkRdnGopq9Vq0u7o2Ypr0gN4Ut/ao28= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711300053; c=relaxed/simple; bh=8wYWk+lnFSA1f2NjZ4HWprJzO1phQiGDLipkeklGi8o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=A5kOiTivjAM4IZvaWNuX2dptKVINqz1VGvTzyOCf0IRIqRtC0CLwH87dLXKYE0dlZlZw3mj3pxfdGxVzFQM4hRX6vhUhdF2kh8GknkZm+G4qO6hK8lBTVXeinV3EaOtG1GF7ohIvVrd1kYBnI7XiS6Gsz1gaTA5vJN0sPSbj/Ww= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZWeYiKcE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZWeYiKcE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44D24C433A6; Sun, 24 Mar 2024 17:07:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711300053; bh=8wYWk+lnFSA1f2NjZ4HWprJzO1phQiGDLipkeklGi8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZWeYiKcEZ28kZcKA/nh1G/gxyAW0FzpZ14nFSFKyxTORqqm3VA2KkLDDinJoI6yhl QyCbtDqgINoKnQcscsrVUaMvliCUkotYZ4hNz2ZgtOGMibRO94YPP42jDyxo5m6GKN kllwvdkoAtOxZUvfnWLkatJOSzIaFhNekdjlu5hj0jJK8/9/ykzuBrAGOUQG0h2e/f 3SL7OVLisu5KFDhVXJA67EuLRpIPBNi7LZ5e8QaW90I21QKkss2fZIjPxRsozttcAF yaaA1vbtb10+q13y2/baIztznpbmpi5YJuf8wpDU++pwi4RJr+IOCAkLMRr0r1U0Em 9jE3FfTpHOFJQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Roman Smirnov , Sergey Shtylyov , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 2/2] block: prevent division by zero in blk_rq_stat_sum() Date: Sun, 24 Mar 2024 13:07:27 -0400 Message-ID: <20240324170729.546679-2-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324170729.546679-1-sashal@kernel.org> References: <20240324170729.546679-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.213 Content-Transfer-Encoding: 8bit From: Roman Smirnov [ 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 Reviewed-by: Sergey Shtylyov Link: https://lore.kernel.org/r/20240305134509.23108-1-r.smirnov@omp.ru Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- 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 ae3dd1fb8e61d..6e602f9b966e4 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