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 A782814600E; Thu, 11 Apr 2024 10:24:44 +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=1712831084; cv=none; b=ooOoUyODatBAnqGedmyAHYTFUV9/ebez4jJPmDjsyLpZwbDgNxExTZ9WWNz/iyZYYENZThTktGZOCnOh6tUVcESsbRBexqnuJ9y9qBgEhlXCTQNYTtHC4Xbd4q6aKl4iZXpuX93y0wnoWes+REDtYZP2tVmj8xsheh1qkT3NJB0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712831084; c=relaxed/simple; bh=51tYNEo6f0EIPrWeR6c1Ycs02DnpMuvcCEdw3QVs3iw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OlH3BBrwHjh5arTPg1uaBpNAJg5vjxYrTRmyc6HfHlpUq+Bp3Sj/QMwCCEqlO84J53OJ9pjnVL5Y5GLi6krhYAdH/iA/aRgrqSbp3JAQUIDbp78T2V2qFaKiXEWh+Ass29WLHJhI7LyDAtUlnOiXn2PQi9+nRNRvelQ7T8toGhw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=o/8zS13k; 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="o/8zS13k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CD7AC433F1; Thu, 11 Apr 2024 10:24:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712831084; bh=51tYNEo6f0EIPrWeR6c1Ycs02DnpMuvcCEdw3QVs3iw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o/8zS13kuDFwAUKucIWTYUfukFVCR+asXFY1F1sW+KRcNgovkBpTSHSja+cdSm3pZ 98/sF8U6FeRcX14TXVXEehjg5UCVam0xsaDzkj691F7s8163BdqDZzarxgpGvGxqbt ZUd1uTDgdhl8mWeZeSfW96SK4/Uf1ErRh3KkVlvw= 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 5.4 193/215] block: prevent division by zero in blk_rq_stat_sum() Date: Thu, 11 Apr 2024 11:56:42 +0200 Message-ID: <20240411095430.663106673@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095424.875421572@linuxfoundation.org> References: <20240411095424.875421572@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 5.4-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 940f15d600f8a..af482d8f9f7a4 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