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 E7E911465BF; Thu, 11 Apr 2024 10:47:16 +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=1712832437; cv=none; b=ZY5EzcAUS9DOqPWi3ChRT5rwb2EeCENg8wNcmkkxYen9UJjmGCM134CBFLL/fF+iUBsZGiw4S9nb4UD2PCJihYFdubpWOq8kJHFyl6mphS5b3jAsEBegeF4eAAiDv8zzE2Ym6TQuBV+GK2O4aPnSe7rMHCdv6EUAARSHbexFrzs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712832437; c=relaxed/simple; bh=tDUtqd4JB4sjZJLUI55/9a+oGVh0O0tb2an0/bi8WyE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cCEPXPdUOsOO8qGQGq5c6+3lkKg1Jm2Gssf6GCHEt/GZ306Vi2qvvFzQOplrjTPthXco9RyWjd+sb7zjKn7CZ53O9p1Y0/6/9oZeEd/0tTBeEYdtRHMAizbFlPlg1uTr02OkMsyBZllpGlgHMENvBMnomC1o2jci0tx9IHM7r24= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lp8Co8rk; 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="lp8Co8rk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70010C433C7; Thu, 11 Apr 2024 10:47:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712832436; bh=tDUtqd4JB4sjZJLUI55/9a+oGVh0O0tb2an0/bi8WyE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lp8Co8rkYJDIbRf0Aaan2OCKfsQMiO/kwgoTlvBxcaRk3M3VoE8ZbClCszJIuG4zm Cwi3d9dBhEOkagGn1c9ERBsaVSLlaDIaXqJfUVKLf2ofg36JLhH+L539HNYHqywoZY fck+OIodiT8/jwLUZjJtPqZdseQU/BaRAnzBFGmE= 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 6.1 49/83] block: prevent division by zero in blk_rq_stat_sum() Date: Thu, 11 Apr 2024 11:57:21 +0200 Message-ID: <20240411095414.160336101@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095412.671665933@linuxfoundation.org> References: <20240411095412.671665933@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-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 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