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 B3713225CD; Sun, 24 Mar 2024 17:06:09 +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=1711299969; cv=none; b=V2TLwG0HXH/W5xMx0hfHqY+lJrX9Wwpb1ujnVpjEp1YaqdO5DzJIhjrDusIOieeetgVYax/OlJDGu35tNoYVE50BfGtCFwviP459qZnprm+c4MSAeAhBt4rTvBepTff1bXhKhU7PTPPoGjFK9Eln12ycQdCEYhMH4ekSUrlExYY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711299969; c=relaxed/simple; bh=0pqNxaLcbkQ7KCRmakADyDfAYk41/fLh/4lRyyT542Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YbSrAffPtWHCPhDdoq03udYWaDXlTuoBoKTqys1fajlaeZMr0H3Z2F2DwGedFcQL3U+deh87yK929XB4+o9w+eI4P3hyDSVGdE5aBp6HoWK1lPJtSSIXLfkMcNkKQdb3PYE92keuWme5Ds2MeI+mKJ9XZQvYkCl03d5YIlzLeZA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BfCIP953; 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="BfCIP953" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB5FEC433F1; Sun, 24 Mar 2024 17:06:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711299969; bh=0pqNxaLcbkQ7KCRmakADyDfAYk41/fLh/4lRyyT542Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BfCIP9536KgM62l08U4KERfYAuWN82hyZ//zgrxQyirMgSuHUi4dExo9Zmwuj+VH+ 0Xl0YycYVCZtsx4aj75QVYcaIOw4YgX9ul+0H21uT6C6ApUOIQWTlsAFqYKGigVK8n G++/Xogv/CLedQJEL1G+2sywWk1I1L9jT4HWxnXWnf5B88zd3BcR4CA2B/F64dnDae 5NtECnRQQDrJ8VN1AcMbPxy9ri3ePKYq44ye6Ykmxc2aQeGcntgL2Jm2KExHlfTRZF 43uT6g2xiIm1pp6OG/fe1unmjxSgIIq1ne8pqDdAIxmd9puePeW+q0nvKghsDkuZv9 UWzf0PPrwvKFA== 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 6.8 08/11] block: prevent division by zero in blk_rq_stat_sum() Date: Sun, 24 Mar 2024 13:05:43 -0400 Message-ID: <20240324170552.545730-8-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324170552.545730-1-sashal@kernel.org> References: <20240324170552.545730-1-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 6.8.1 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 7ff76ae6c76a9..e42c263e53fb9 100644 --- a/block/blk-stat.c +++ b/block/blk-stat.c @@ -27,7 +27,7 @@ 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