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 ADAAC16DD36; Fri, 29 Mar 2024 12:49:47 +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=1711716587; cv=none; b=cdnhAtLj3tiPhVAC92UArB5Iyh0cheqDDO1wk0C69Vh6SsiWR9vydPnmw7f9XrSX16Lr1MmWpwEvB6yz/EwTOO+d23xANQnZLWgJZNG4F9NxGXGfB91wmvZw5y0wJK512nCGLY7KXVmDd9sIKJoKcSJCY74JCIYme58qqp6HGcI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711716587; c=relaxed/simple; bh=8wYWk+lnFSA1f2NjZ4HWprJzO1phQiGDLipkeklGi8o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JzxUWZLXK0OZ9TWkVWoJX+hjw8GEg9IiF+FDC/6nEQP2iU251+WMn55t8pgoqxinfz97bY1Eoc26pXDbJQr4ScwP2PFzC2UtQTYzifFkHdpOyFu2gmpRhKaVrg80+VbjFmL5Cute6P6g+bDFoI3FiYfj/FhYiY+lTJnGZLmofy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mHRn5aAt; 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="mHRn5aAt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C20C0C43394; Fri, 29 Mar 2024 12:49:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711716587; bh=8wYWk+lnFSA1f2NjZ4HWprJzO1phQiGDLipkeklGi8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mHRn5aAt/PoRiJIrw4OIUpfcVcOIbjlUrrGAqVvR6fvn5+PkbMaRt5fUZGslZRdS5 /z9s1UvnxkQnD7IiAUiMz+kb8VHab+/7ZZHMIbc7Q7NDd6P+XMWdfqzFyh9uA9CKtx BwJzJlHFn6R1UQgTYiWqpeAl0esyx0GKzGcsZw03CTwqFtuOfg4GeK2veRBG/9kpeN U9cfMy+Xr0qvoQAFsfOQpkCashocHiIYsKtO+HlKRWTy/NAS+0/HIRIqHSChBHlrhu 12R6HCD5GeBIBfQMNkZzjxPzEdkrkjb6/wFW4HYzZJgmCMLhJwGHCtZHRK/69X7AJw hgj0Y1UqT8xMQ== 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 26/31] block: prevent division by zero in blk_rq_stat_sum() Date: Fri, 29 Mar 2024 08:48:43 -0400 Message-ID: <20240329124903.3093161-26-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240329124903.3093161-1-sashal@kernel.org> References: <20240329124903.3093161-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.214 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