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 F27EF223302; Thu, 12 Dec 2024 15:44:41 +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=1734018282; cv=none; b=f3Q2x0r/1syVu9XZvXIJGiy6rZKwVKxoCODnIJg57y1oZEurJ6cfeZfuuym3QwOclHv5vOhStaP9ydJH2OUBUO6Sv9/gez0l5RrJT2o95+ZarU7obUq5nsnDdqpuiKTkDFPyyyctoSdkZ6ifMSC88a/1MED4vyCzh52RxtAeMBU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734018282; c=relaxed/simple; bh=xpsv5ml1yJ68KsNoIBgfph2KZyP61XWM/aIjaYNMRHU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IbOP7BplPaSEkwxrad7nroJDPq0zy4N8WqIjR9LLzehmHaaaXtEaQJFBvBzrPSc+cyvXSRoRwJXLA/yeNuBhMRmoMBlzP8gEADGuQrLwJDIdSwfwkZ/GeqNSOV4tVfWpgvINI/i6k3SONPy06zM5taaSnb5SuwFQSpcbZjXmtp4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=asRa8d7Z; 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="asRa8d7Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C461C4CECE; Thu, 12 Dec 2024 15:44:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734018281; bh=xpsv5ml1yJ68KsNoIBgfph2KZyP61XWM/aIjaYNMRHU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=asRa8d7ZPl0mYVDPKxkxnZIhUa4NZk6PH/Ep5htvD5kf2+uK3/os1BH4NE7SLIXh6 iyfB7nYkfGKy3o2AwQ84j49dpi+kYeRkhfFD+eQfQoLUgU7yk0iTW2pZ689UG8t7W4 iPVHasT5rV5vQ+EtnTSDhLTRkA77OXLI0lms7EGw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Si-Wei Liu" , Darren Kenny , Xuan Zhuo , Jason Wang , Paolo Abeni , Sasha Levin Subject: [PATCH 6.6 249/356] virtio-net: fix overflow inside virtnet_rq_alloc Date: Thu, 12 Dec 2024 15:59:28 +0100 Message-ID: <20241212144254.442545847@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241212144244.601729511@linuxfoundation.org> References: <20241212144244.601729511@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: Xuan Zhuo [ Upstream commit 6aacd1484468361d1d04badfe75f264fa5314864 ] When the frag just got a page, then may lead to regression on VM. Specially if the sysctl net.core.high_order_alloc_disable value is 1, then the frag always get a page when do refill. Which could see reliable crashes or scp failure (scp a file 100M in size to VM). The issue is that the virtnet_rq_dma takes up 16 bytes at the beginning of a new frag. When the frag size is larger than PAGE_SIZE, everything is fine. However, if the frag is only one page and the total size of the buffer and virtnet_rq_dma is larger than one page, an overflow may occur. The commit f9dac92ba908 ("virtio_ring: enable premapped mode whatever use_dma_api") introduced this problem. And we reverted some commits to fix this in last linux version. Now we try to enable it and fix this bug directly. Here, when the frag size is not enough, we reduce the buffer len to fix this problem. Reported-by: "Si-Wei Liu" Tested-by: Darren Kenny Signed-off-by: Xuan Zhuo Acked-by: Jason Wang Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/virtio_net.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 426c05d5b1381..3bf394b24d971 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -676,9 +676,6 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp) void *buf, *head; dma_addr_t addr; - if (unlikely(!skb_page_frag_refill(size, alloc_frag, gfp))) - return NULL; - head = page_address(alloc_frag->page); if (rq->do_dma) { @@ -1860,6 +1857,9 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, len = SKB_DATA_ALIGN(len) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + if (unlikely(!skb_page_frag_refill(len, &rq->alloc_frag, gfp))) + return -ENOMEM; + buf = virtnet_rq_alloc(rq, len, gfp); if (unlikely(!buf)) return -ENOMEM; @@ -1962,6 +1962,12 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, */ len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room); + if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp))) + return -ENOMEM; + + if (!alloc_frag->offset && len + room + sizeof(struct virtnet_rq_dma) > alloc_frag->size) + len -= sizeof(struct virtnet_rq_dma); + buf = virtnet_rq_alloc(rq, len + room, gfp); if (unlikely(!buf)) return -ENOMEM; -- 2.43.0