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 7F89E260586; Tue, 26 Aug 2025 14:29:14 +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=1756218554; cv=none; b=gp4QUL13oT5KmEY5TUORyUnFyE5sVjR0BRpFGCDGcVYdvBZHAWJdS/HICayE6gDDDa3uPIYdbc+lAK5SNbWNhT+bUbt9w/KD0+mbdc7KUEz+3CPAF7rms1zapCA4PWf8ibhwVff9ygsQi/d1y0731xjNuNkLhRB/tClUWIYrhjQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218554; c=relaxed/simple; bh=jjMXoI7LDzuCmy1GxBTe+4raM5wG4caeOIRFoXhukuo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LLR5FAAwgo66c+ZnEaiCfHr1IjoInr0HBHUcTiJrSy1rZcCCvZI2lw6WHsNuLiwkrlf8p2ZCTBYm00HEeuckNAXpjHJZFL8R3iTo+3TpZwiDJk+6PT5H6QLZs96OKhi/XvZULVR3P8cLjiqxS6hXqrMKcckiYiB3oCl9untaL74= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zP4npiEk; 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="zP4npiEk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11098C113CF; Tue, 26 Aug 2025 14:29:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756218554; bh=jjMXoI7LDzuCmy1GxBTe+4raM5wG4caeOIRFoXhukuo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zP4npiEkja+ouX7375g9NtDUrdqbdtYWhDhU7QzPdFePY1LP9IjEN3Uarz5JAkxvL 6eUDNthrU+B4Z9m9b/iCncKQU6s69a5aR2K4kk0/+LxZbIfYiDI/2MLEY4Y5IZ9AsR m8goo1FW6yMwuLKSdIBSypjptMUy6oH5O9Z9aDo8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bui Quang Minh , Jason Wang , Paolo Abeni , Sasha Levin Subject: [PATCH 5.4 043/403] virtio-net: ensure the received length does not exceed allocated size Date: Tue, 26 Aug 2025 13:06:09 +0200 Message-ID: <20250826110907.016284633@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110905.607690791@linuxfoundation.org> References: <20250826110905.607690791@linuxfoundation.org> User-Agent: quilt/0.68 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 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bui Quang Minh commit 315dbdd7cdf6aa533829774caaf4d25f1fd20e73 upstream. In xdp_linearize_page, when reading the following buffers from the ring, we forget to check the received length with the true allocate size. This can lead to an out-of-bound read. This commit adds that missing check. Cc: Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set") Signed-off-by: Bui Quang Minh Acked-by: Jason Wang Link: https://patch.msgid.link/20250630144212.48471-2-minhquangbui99@gmail.com Signed-off-by: Paolo Abeni [ adapted virtqueue_get_buf() to virtqueue_get_buf_ctx() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-) --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -394,6 +394,26 @@ static unsigned int mergeable_ctx_to_tru return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1); } +static int check_mergeable_len(struct net_device *dev, void *mrg_ctx, + unsigned int len) +{ + unsigned int headroom, tailroom, room, truesize; + + truesize = mergeable_ctx_to_truesize(mrg_ctx); + headroom = mergeable_ctx_to_headroom(mrg_ctx); + tailroom = headroom ? sizeof(struct skb_shared_info) : 0; + room = SKB_DATA_ALIGN(headroom + tailroom); + + if (len > truesize - room) { + pr_debug("%s: rx error: len %u exceeds truesize %lu\n", + dev->name, len, (unsigned long)(truesize - room)); + dev->stats.rx_length_errors++; + return -1; + } + + return 0; +} + /* Called from bottom half context */ static struct sk_buff *page_to_skb(struct virtnet_info *vi, struct receive_queue *rq, @@ -639,7 +659,8 @@ static unsigned int virtnet_get_headroom * across multiple buffers (num_buf > 1), and we make sure buffers * have enough headroom. */ -static struct page *xdp_linearize_page(struct receive_queue *rq, +static struct page *xdp_linearize_page(struct net_device *dev, + struct receive_queue *rq, u16 *num_buf, struct page *p, int offset, @@ -659,18 +680,27 @@ static struct page *xdp_linearize_page(s memcpy(page_address(page) + page_off, page_address(p) + offset, *len); page_off += *len; + /* Only mergeable mode can go inside this while loop. In small mode, + * *num_buf == 1, so it cannot go inside. + */ while (--*num_buf) { unsigned int buflen; void *buf; + void *ctx; int off; - buf = virtqueue_get_buf(rq->vq, &buflen); + buf = virtqueue_get_buf_ctx(rq->vq, &buflen, &ctx); if (unlikely(!buf)) goto err_buf; p = virt_to_head_page(buf); off = buf - page_address(p); + if (check_mergeable_len(dev, ctx, buflen)) { + put_page(p); + goto err_buf; + } + /* guard against a misconfigured or uncooperative backend that * is sending packet larger than the MTU. */ @@ -745,7 +775,7 @@ static struct sk_buff *receive_small(str headroom = vi->hdr_len + header_offset; buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - xdp_page = xdp_linearize_page(rq, &num_buf, page, + xdp_page = xdp_linearize_page(dev, rq, &num_buf, page, offset, header_offset, &tlen); if (!xdp_page) @@ -910,7 +940,7 @@ static struct sk_buff *receive_mergeable if (unlikely(num_buf > 1 || headroom < virtnet_get_headroom(vi))) { /* linearize data for XDP */ - xdp_page = xdp_linearize_page(rq, &num_buf, + xdp_page = xdp_linearize_page(dev, rq, &num_buf, page, offset, VIRTIO_XDP_HEADROOM, &len);