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 C54FF146D4E; Thu, 11 Apr 2024 10:28:18 +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=1712831298; cv=none; b=HcfNWVUIQrMKe5wmY+TtjKvVNTosdnmgQ84XIraDeXP+yLEtoAfioBMfRA7b7nj8/tGH9XhDSDarChXEGzBK8jyhCdpt+UAOWo0r9VDuWKa287bJ0Pz1ydaWUNwIDi/69TC8ksTGmymWVfZ0W5EF7EYOOSzm3gJliF6A2j5lGC0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712831298; c=relaxed/simple; bh=ZO6Sgarui4uwepfsw47kn+VJ6H7Fuoc1jaK8mGglfAA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rE01wfVasRBPmuGi93Pn/kFdarwaFJ4o2aePc3FWtiM5c5vFDJJKIbRB6UwKbYTbeLyGhvIuNVenOB4KZ+JPszBSKJ3y9au4TWnuqhQMxNdSHUi+KBTO66yMEk7hn1uSopEhaPmScyrEXXw/RMv9w12ZqPi2nmJhzGI4/j7nlOU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DKvH/ymO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="DKvH/ymO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E6E0C433F1; Thu, 11 Apr 2024 10:28:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712831298; bh=ZO6Sgarui4uwepfsw47kn+VJ6H7Fuoc1jaK8mGglfAA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DKvH/ymOlGt+GLFByKBBZbKAnqP5AKnIE4lNnrojpWWlU+bjScPjccGv3OBn122gL s1faSjiXy1XIOxoGaAW43Ep02nRqoM23hUH/d6LD23TGlnXIaTaDqptgiDDbSxucdn Tpauh72/n0zntPi1xeASZ4X22Qo//6wcPhyHk8UQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Roman Smirnov , Sergey Shtylyov , Jens Axboe , Sasha Levin Subject: [PATCH 6.6 076/114] block: prevent division by zero in blk_rq_stat_sum() Date: Thu, 11 Apr 2024 11:56:43 +0200 Message-ID: <20240411095419.181868030@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095416.853744210@linuxfoundation.org> References: <20240411095416.853744210@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ 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