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 742DA59158; Sun, 24 Mar 2024 17:07:18 +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=1711300038; cv=none; b=hiNC7NcX7yhzLs0IvMHomkPpd6S7gdfUuBhgx5hiO4th2lusP/+8Jl6bCI1yP86xbiIJip2U1pKreKAdXIBxP4kglDGS5uTFYac0AT+U8VYneVf6v74kRirQnpKh3p3TZPgZ832WW2HSI2aqN6I1vvEepUbaBP+aOgxREN41Kso= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711300038; c=relaxed/simple; bh=Yx4z1c+Bu5s+V0sWrTPLA22MMO08Ob0bgjwlHnhaN5k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SVsGUFxeyM/TV7tZIGlobBAZdbEqMq5UXBR5SbNWl1nxQaCQzs+B2WtPU9zWuvDe4EPm2uK944UnZCKdyDoB/VPgDoC8UEntgO/w4GFh1T/oILOp4oHtwjagCrEUZ6F2oK++LEdqrgGi5MiLcK5LQSnh+GK3r+569YVOMtkBoGY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Qhu/ugFC; 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="Qhu/ugFC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8492FC43390; Sun, 24 Mar 2024 17:07:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711300038; bh=Yx4z1c+Bu5s+V0sWrTPLA22MMO08Ob0bgjwlHnhaN5k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qhu/ugFC8g/wEVOzJigUxqLi/1qWbze92wf2LX3jVZlgpVzlbiItR9syCTUtCTuAr O9utODEWKrrocjKMELrCo9gDJx2P7pnZ59yUfBRMCuAKzqKIZPy/Eto15NluIk508+ w6zy5A1c6w0Hb4qwWqzV3lwSYeh3ifs6ShHL/fmQCoANefco6v7L6WJT016hUV22B/ h70hs+t/ZQt+7Htw70obce4lsXzpk+aklVb/3bKjvFN4YZTIq/9BRv8SMXxbSWzm+l QbzLkYi/+k9eL69ns9FiyTFDqYcP074Fj0b+BSzl2lojmEPC2NOGrjI7zUGXC8loL/ gY/EunlTvl+rA== 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 6.1 5/7] block: prevent division by zero in blk_rq_stat_sum() Date: Sun, 24 Mar 2024 13:07:05 -0400 Message-ID: <20240324170709.546465-5-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324170709.546465-1-sashal@kernel.org> References: <20240324170709.546465-1-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 6.1.82 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 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