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 947FA2114; Tue, 23 Jan 2024 02:09:54 +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=1705975794; cv=none; b=hYXnvK4ysIA5xDIHoJrCvKYOgjK0qh+ZoClhnw6DsMEZH5GkG0LJiU2sDhP3yGXEHnJwkKZapbmhetyRUEmPVstQ0Iw81hbf1qBEm0Kx6IrtBbOk7v6KxP4MXaNuqM7DaXMwYHgMtjDLpYBqXUY0z3mGgrqd8TxRe2TYB5dihzM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705975794; c=relaxed/simple; bh=YVc4Ww0LxZLjkwhOe0IeqiUarJi2NWjiuvIIEYfxT/M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eN3X26d3lZrqeYi5Zgoqni/XKXkCjbV0egLpuYhcyvACsVm0uUvnxAOLt0Ohxo50LqP1sXO6ww0sDOfllA28+0FtcO1w/2601k00wnon/gFSYu3+OI4oCCPB6zZqQ2pAcIKfRfz1RgoU1EbynRBQjOWiJzsToNSPleLpv1DgpRs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NCCoC7Co; 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="NCCoC7Co" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BA4FC433F1; Tue, 23 Jan 2024 02:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705975794; bh=YVc4Ww0LxZLjkwhOe0IeqiUarJi2NWjiuvIIEYfxT/M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NCCoC7CogVbun70Vq5NXZvWDSkbYgQriMDtWN/dNQD0G5bw/E4M5Ne4rWi2MhRmBf elbiNhyZw2hUmoWr6hnA2ghbiojr3wHoPbfrUF92W+qn5EDe4NYFONYdaa5cDOzIrw w24/vJUBoIGlWnTG3XlEDaV68mf1aKAu3H6y1o7o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+7f4d0ea3df4d4fa9a65f@syzkaller.appspotmail.com, Eric Dumazet , Willem de Bruijn , "David S. Miller" , Sasha Levin Subject: [PATCH 6.6 542/583] net: add more sanity check in virtio_net_hdr_to_skb() Date: Mon, 22 Jan 2024 15:59:53 -0800 Message-ID: <20240122235828.708763031@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235812.238724226@linuxfoundation.org> References: <20240122235812.238724226@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 9181d6f8a2bb32d158de66a84164fac05e3ddd18 ] syzbot/KMSAN reports access to uninitialized data from gso_features_check() [1] The repro use af_packet, injecting a gso packet and hdrlen == 0. We could fix the issue making gso_features_check() more careful while dealing with NETIF_F_TSO_MANGLEID in fast path. Or we can make sure virtio_net_hdr_to_skb() pulls minimal network and transport headers as intended. Note that for GSO packets coming from untrusted sources, SKB_GSO_DODGY bit forces a proper header validation (and pull) before the packet can hit any device ndo_start_xmit(), thus we do not need a precise disection at virtio_net_hdr_to_skb() stage. [1] BUG: KMSAN: uninit-value in skb_gso_segment include/net/gso.h:83 [inline] BUG: KMSAN: uninit-value in validate_xmit_skb+0x10f2/0x1930 net/core/dev.c:3629 skb_gso_segment include/net/gso.h:83 [inline] validate_xmit_skb+0x10f2/0x1930 net/core/dev.c:3629 __dev_queue_xmit+0x1eac/0x5130 net/core/dev.c:4341 dev_queue_xmit include/linux/netdevice.h:3134 [inline] packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3087 [inline] packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x318/0x740 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2780 packet_alloc_skb net/packet/af_packet.c:2936 [inline] packet_snd net/packet/af_packet.c:3030 [inline] packet_sendmsg+0x70e8/0x9f30 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 5025 Comm: syz-executor279 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Reported-by: syzbot+7f4d0ea3df4d4fa9a65f@syzkaller.appspotmail.com Link: https://lore.kernel.org/netdev/0000000000005abd7b060eb160cd@google.com/ Fixes: 9274124f023b ("net: stricter validation of untrusted gso packets") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/linux/virtio_net.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 27cc1d464321..4dfa9b69ca8d 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -3,6 +3,8 @@ #define _LINUX_VIRTIO_NET_H #include +#include +#include #include #include #include @@ -49,6 +51,7 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, const struct virtio_net_hdr *hdr, bool little_endian) { + unsigned int nh_min_len = sizeof(struct iphdr); unsigned int gso_type = 0; unsigned int thlen = 0; unsigned int p_off = 0; @@ -65,6 +68,7 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, gso_type = SKB_GSO_TCPV6; ip_proto = IPPROTO_TCP; thlen = sizeof(struct tcphdr); + nh_min_len = sizeof(struct ipv6hdr); break; case VIRTIO_NET_HDR_GSO_UDP: gso_type = SKB_GSO_UDP; @@ -100,7 +104,8 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, if (!skb_partial_csum_set(skb, start, off)) return -EINVAL; - p_off = skb_transport_offset(skb) + thlen; + nh_min_len = max_t(u32, nh_min_len, skb_transport_offset(skb)); + p_off = nh_min_len + thlen; if (!pskb_may_pull(skb, p_off)) return -EINVAL; } else { @@ -140,7 +145,7 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, skb_set_transport_header(skb, keys.control.thoff); } else if (gso_type) { - p_off = thlen; + p_off = nh_min_len + thlen; if (!pskb_may_pull(skb, p_off)) return -EINVAL; } -- 2.43.0