user/sven/linux.git/include/linux/virtio_net.h, branch v5.4.122

virtio_net: Do not pull payload in skb->head

2021-05-22T09:38:28Z

[ Upstream commit 0f6925b3e8da0dbbb52447ca8a8b42b371aac7db ] Xuan Zhuo reported that commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for tiny skbs") brought a ~10% performance drop. The reason for the performance drop was that GRO was forced to chain sk_buff (using skb_shinfo(skb)->frag_list), which uses more memory but also cause packet consumers to go over a lot of overhead handling all the tiny skbs. It turns out that virtio_net page_to_skb() has a wrong strategy : It allocates skbs with GOOD_COPY_LEN (128) bytes in skb->head, then copies 128 bytes from the page, before feeding the packet to GRO stack. This was suboptimal before commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for tiny skbs") because GRO was using 2 frags per MSS, meaning we were not packing MSS with 100% efficiency. Fix is to pull only the ethernet header in page_to_skb() Then, we change virtio_net_hdr_to_skb() to pull the missing headers, instead of assuming they were already pulled by callers. This fixes the performance regression, but could also allow virtio_net to accept packets with more than 128bytes of headers. Many thanks to Xuan Zhuo for his report, and his tests/help. Fixes: 3226b158e67c ("net: avoid 32 x truesize under-estimation for tiny skbs") Reported-by: Xuan Zhuo Link: https://www.spinics.net/lists/netdev/msg731397.html Co-Developed-by: Xuan Zhuo Signed-off-by: Xuan Zhuo Signed-off-by: Eric Dumazet Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: virtualization@lists.linux-foundation.org Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: ensure mac header is set in virtio_net_hdr_to_skb()

2021-04-14T06:24:12Z

commit 61431a5907fc36d0738e9a547c7e1556349a03e9 upstream. Commit 924a9bc362a5 ("net: check if protocol extracted by virtio_net_hdr_set_proto is correct") added a call to dev_parse_header_protocol() but mac_header is not yet set. This means that eth_hdr() reads complete garbage, and syzbot complained about it [1] This patch resets mac_header earlier, to get more coverage about this change. Audit of virtio_net_hdr_to_skb() callers shows that this change should be safe. [1] BUG: KASAN: use-after-free in eth_header_parse_protocol+0xdc/0xe0 net/ethernet/eth.c:282 Read of size 2 at addr ffff888017a6200b by task syz-executor313/8409 CPU: 1 PID: 8409 Comm: syz-executor313 Not tainted 5.12.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 eth_header_parse_protocol+0xdc/0xe0 net/ethernet/eth.c:282 dev_parse_header_protocol include/linux/netdevice.h:3177 [inline] virtio_net_hdr_to_skb.constprop.0+0x99d/0xcd0 include/linux/virtio_net.h:83 packet_snd net/packet/af_packet.c:2994 [inline] packet_sendmsg+0x2325/0x52b0 net/packet/af_packet.c:3031 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 sock_no_sendpage+0xf3/0x130 net/core/sock.c:2860 kernel_sendpage.part.0+0x1ab/0x350 net/socket.c:3631 kernel_sendpage net/socket.c:3628 [inline] sock_sendpage+0xe5/0x140 net/socket.c:947 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] do_splice+0xb7e/0x1940 fs/splice.c:1079 __do_splice+0x134/0x250 fs/splice.c:1144 __do_sys_splice fs/splice.c:1350 [inline] __se_sys_splice fs/splice.c:1332 [inline] __x64_sys_splice+0x198/0x250 fs/splice.c:1332 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 Fixes: 924a9bc362a5 ("net: check if protocol extracted by virtio_net_hdr_set_proto is correct") Signed-off-by: Eric Dumazet Cc: Balazs Nemeth Cc: Willem de Bruijn Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: check if protocol extracted by virtio_net_hdr_set_proto is correct

2021-03-17T16:03:30Z

commit 924a9bc362a5223cd448ca08c3dde21235adc310 upstream. For gso packets, virtio_net_hdr_set_proto sets the protocol (if it isn't set) based on the type in the virtio net hdr, but the skb could contain anything since it could come from packet_snd through a raw socket. If there is a mismatch between what virtio_net_hdr_set_proto sets and the actual protocol, then the skb could be handled incorrectly later on. An example where this poses an issue is with the subsequent call to skb_flow_dissect_flow_keys_basic which relies on skb->protocol being set correctly. A specially crafted packet could fool skb_flow_dissect_flow_keys_basic preventing EINVAL to be returned. Avoid blindly trusting the information provided by the virtio net header by checking that the protocol in the packet actually matches the protocol set by virtio_net_hdr_set_proto. Note that since the protocol is only checked if skb->dev implements header_ops->parse_protocol, packets from devices without the implementation are not checked at this stage. Fixes: 9274124f023b ("net: stricter validation of untrusted gso packets") Signed-off-by: Balazs Nemeth Acked-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: be more gentle about silly gso requests coming from user

2020-06-10T18:24:55Z

[ Upstream commit 7c6d2ecbda83150b2036a2b36b21381ad4667762 ] Recent change in virtio_net_hdr_to_skb() broke some packetdrill tests. When --mss=XXX option is set, packetdrill always provide gso_type & gso_size for its inbound packets, regardless of packet size. if (packet->tcp && packet->mss) { if (packet->ipv4) gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; else gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; gso.gso_size = packet->mss; } Since many other programs could do the same, relax virtio_net_hdr_to_skb() to no longer return an error, but instead ignore gso settings. This keeps Willem intent to make sure no malicious packet could reach gso stack. Note that TCP stack has a special logic in tcp_set_skb_tso_segs() to clear gso_size for small packets. Fixes: 6dd912f82680 ("net: check untrusted gso_size at kernel entry") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Acked-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: check untrusted gso_size at kernel entry

2020-06-10T18:24:55Z

[ Upstream commit 6dd912f82680761d8fb6b1bb274a69d4c7010988 ] Syzkaller again found a path to a kernel crash through bad gso input: a packet with gso size exceeding len. These packets are dropped in tcp_gso_segment and udp[46]_ufo_fragment. But they may affect gso size calculations earlier in the path. Now that we have thlen as of commit 9274124f023b ("net: stricter validation of untrusted gso packets"), check gso_size at entry too. Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.") Reported-by: syzbot Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: stricter validation of untrusted gso packets

2020-05-14T05:58:21Z

[ Upstream commit 9274124f023b5c56dc4326637d4f787968b03607 ] Syzkaller again found a path to a kernel crash through bad gso input: a packet with transport header extending beyond skb_headlen(skb). Tighten validation at kernel entry: - Verify that the transport header lies within the linear section. To avoid pulling linux/tcp.h, verify just sizeof tcphdr. tcp_gso_segment will call pskb_may_pull (th->doff * 4) before use. - Match the gso_type against the ip_proto found by the flow dissector. Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.") Reported-by: syzbot Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-02-24T20:06:19Z

Three conflicts, one of which, for marvell10g.c is non-trivial and requires some follow-up from Heiner or someone else. The issue is that Heiner converted the marvell10g driver over to use the generic c45 code as much as possible. However, in 'net' a bug fix appeared which makes sure that a new local mask (MDIO_AN_10GBT_CTRL_ADV_NBT_MASK) with value 0x01e0 is cleared. Signed-off-by: David S. Miller

net: Don't set transport offset to invalid value

2019-02-22T20:55:31Z

If the socket was created with socket(AF_PACKET, SOCK_RAW, 0), skb->protocol will be unset, __skb_flow_dissect() will fail, and skb_probe_transport_header() will fall back to the offset_hint, making the resulting skb_transport_offset incorrect. If, however, there is no transport header in the packet, transport_header shouldn't be set to an arbitrary value. Fix it by leaving the transport offset unset if it couldn't be found, to be explicit rather than to fill it with some wrong value. It changes the behavior, but if some code relied on the old behavior, it would be broken anyway, as the old one is incorrect. Signed-off-by: Maxim Mikityanskiy Signed-off-by: David S. Miller

net: avoid false positives in untrusted gso validation

2019-02-21T22:08:13Z

GSO packets with vnet_hdr must conform to a small set of gso_types. The below commit uses flow dissection to drop packets that do not. But it has false positives when the skb is not fully initialized. Dissection needs skb->protocol and skb->network_header. Infer skb->protocol from gso_type as the two must agree. SKB_GSO_UDP can use both ipv4 and ipv6, so try both. Exclude callers for which network header offset is not known. Fixes: d5be7f632bad ("net: validate untrusted gso packets without csum offload") Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

net: validate untrusted gso packets without csum offload

2019-02-16T04:30:37Z

Syzkaller again found a path to a kernel crash through bad gso input. By building an excessively large packet to cause an skb field to wrap. If VIRTIO_NET_HDR_F_NEEDS_CSUM was set this would have been dropped in skb_partial_csum_set. GSO packets that do not set checksum offload are suspicious and rare. Most callers of virtio_net_hdr_to_skb already pass them to skb_probe_transport_header. Move that test forward, change it to detect parse failure and drop packets on failure as those cleary are not one of the legitimate VIRTIO_NET_HDR_GSO types. Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.") Fixes: f43798c27684 ("tun: Allow GSO using virtio_net_hdr") Reported-by: syzbot Signed-off-by: Willem de Bruijn Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller