Revision tags: v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12 |
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#
342c88f4 |
| 12-Jan-2024 |
Eric Dumazet <edumazet@google.com> |
net: add more sanity check in virtio_net_hdr_to_skb()
[ Upstream commit 9181d6f8a2bb32d158de66a84164fac05e3ddd18 ]
syzbot/KMSAN reports access to uninitialized data from gso_features_check() [1]
T
net: add more sanity check in virtio_net_hdr_to_skb()
[ 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 <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Revision tags: v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8 |
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#
fc8b2a61 |
| 11-Oct-2023 |
Willem de Bruijn <willemb@google.com> |
net: more strict VIRTIO_NET_HDR_GSO_UDP_L4 validation
Syzbot reported two new paths to hit an internal WARNING using the new virtio gso type VIRTIO_NET_HDR_GSO_UDP_L4.
RIP: 0010:skb_checksum_he
net: more strict VIRTIO_NET_HDR_GSO_UDP_L4 validation
Syzbot reported two new paths to hit an internal WARNING using the new virtio gso type VIRTIO_NET_HDR_GSO_UDP_L4.
RIP: 0010:skb_checksum_help+0x4a2/0x600 net/core/dev.c:3260 skb len=64521 gso_size=344 and
RIP: 0010:skb_warn_bad_offload+0x118/0x240 net/core/dev.c:3262
Older virtio types have historically had loose restrictions, leading to many entirely impractical fuzzer generated packets causing problems deep in the kernel stack. Ideally, we would have had strict validation for all types from the start.
New virtio types can have tighter validation. Limit UDP GSO packets inserted via virtio to the same limits imposed by the UDP_SEGMENT socket interface:
1. must use checksum offload 2. checksum offload matches UDP header 3. no more segments than UDP_MAX_SEGMENTS 4. UDP GSO does not take modifier flags, notably SKB_GSO_TCP_ECN
Fixes: 860b7f27b8f7 ("linux/virtio_net.h: Support USO offload in vnet header.") Reported-by: syzbot+01cdbc31e9c0ae9b33ac@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/0000000000005039270605eb0b7f@google.com/ Reported-by: syzbot+c99d835ff081ca30f986@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/0000000000005426680605eb0b9f@google.com/ Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3, v6.5.2, v6.1.51, v6.5.1, v6.1.50, v6.5, v6.1.49, v6.1.48, v6.1.46 |
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#
b616be6b |
| 16-Aug-2023 |
Eric Dumazet <edumazet@google.com> |
net: do not allow gso_size to be set to GSO_BY_FRAGS
One missing check in virtio_net_hdr_to_skb() allowed syzbot to crash kernels again [1]
Do not allow gso_size to be set to GSO_BY_FRAGS (0xffff),
net: do not allow gso_size to be set to GSO_BY_FRAGS
One missing check in virtio_net_hdr_to_skb() allowed syzbot to crash kernels again [1]
Do not allow gso_size to be set to GSO_BY_FRAGS (0xffff), because this magic value is used by the kernel.
[1] general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077] CPU: 0 PID: 5039 Comm: syz-executor401 Not tainted 6.5.0-rc5-next-20230809-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:skb_segment+0x1a52/0x3ef0 net/core/skbuff.c:4500 Code: 00 00 00 e9 ab eb ff ff e8 6b 96 5d f9 48 8b 84 24 00 01 00 00 48 8d 78 70 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e ea 21 00 00 48 8b 84 24 00 01 RSP: 0018:ffffc90003d3f1c8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 000000000001fffe RCX: 0000000000000000 RDX: 000000000000000e RSI: ffffffff882a3115 RDI: 0000000000000070 RBP: ffffc90003d3f378 R08: 0000000000000005 R09: 000000000000ffff R10: 000000000000ffff R11: 5ee4a93e456187d6 R12: 000000000001ffc6 R13: dffffc0000000000 R14: 0000000000000008 R15: 000000000000ffff FS: 00005555563f2380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020020000 CR3: 000000001626d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> udp6_ufo_fragment+0x9d2/0xd50 net/ipv6/udp_offload.c:109 ipv6_gso_segment+0x5c4/0x17b0 net/ipv6/ip6_offload.c:120 skb_mac_gso_segment+0x292/0x610 net/core/gso.c:53 __skb_gso_segment+0x339/0x710 net/core/gso.c:124 skb_gso_segment include/net/gso.h:83 [inline] validate_xmit_skb+0x3a5/0xf10 net/core/dev.c:3625 __dev_queue_xmit+0x8f0/0x3d60 net/core/dev.c:4329 dev_queue_xmit include/linux/netdevice.h:3082 [inline] packet_xmit+0x257/0x380 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3087 [inline] packet_sendmsg+0x24c7/0x5570 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:727 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:750 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2496 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2550 __sys_sendmsg+0x117/0x1e0 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff27cdb34d9
Fixes: 3953c46c3ac7 ("sk_buff: allow segmenting based on frag sizes") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Xin Long <lucien.xin@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://lore.kernel.org/r/20230816142158.1779798-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Revision tags: v6.1.45, v6.1.44, v6.1.43, v6.1.42, v6.1.41, v6.1.40, v6.1.39, v6.1.38, v6.1.37, v6.1.36, v6.4, v6.1.35, v6.1.34, v6.1.33, v6.1.32, v6.1.31, v6.1.30, v6.1.29, v6.1.28, v6.1.27, v6.1.26, v6.3, v6.1.25, v6.1.24, v6.1.23, v6.1.22, v6.1.21, v6.1.20, v6.1.19, v6.1.18, v6.1.17, v6.1.16, v6.1.15, v6.1.14, v6.1.13, v6.2, v6.1.12, v6.1.11, v6.1.10, v6.1.9, v6.1.8, v6.1.7, v6.1.6, v6.1.5, v6.0.19, v6.0.18, v6.1.4, v6.1.3, v6.0.17, v6.1.2, v6.0.16, v6.1.1, v6.0.15, v6.0.14, v6.0.13, v6.1, v6.0.12 |
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#
860b7f27 |
| 07-Dec-2022 |
Andrew Melnychenko <andrew@daynix.com> |
linux/virtio_net.h: Support USO offload in vnet header.
Now, it's possible to convert USO vnet packets from/to skb. Added support for GSO_UDP_L4 offload.
Signed-off-by: Andrew Melnychenko <andrew@d
linux/virtio_net.h: Support USO offload in vnet header.
Now, it's possible to convert USO vnet packets from/to skb. Added support for GSO_UDP_L4 offload.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v6.0.11, v6.0.10, v5.15.80, v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71, v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66, v5.15.65, v5.15.64, v5.15.63, v5.15.62, v5.15.61, v5.15.60, v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47, v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35, v5.15.34, v5.15.33, v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27, v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20, v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15, v5.16 |
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#
1ed1d592 |
| 20-Dec-2021 |
Willem de Bruijn <willemb@google.com> |
net: skip virtio_net_hdr_set_proto if protocol already set
virtio_net_hdr_set_proto infers skb->protocol from the virtio_net_hdr gso_type, to avoid packets getting dropped for lack of a proto type.
net: skip virtio_net_hdr_set_proto if protocol already set
virtio_net_hdr_set_proto infers skb->protocol from the virtio_net_hdr gso_type, to avoid packets getting dropped for lack of a proto type.
Its protocol choice is a guess, especially in the case of UFO, where the single VIRTIO_NET_HDR_GSO_UDP label covers both UFOv4 and UFOv6.
Skip this best effort if the field is already initialized. Whether explicitly from userspace, or implicitly based on an earlier call to dev_parse_header_protocol (which is more robust, but was introduced after this patch).
Fixes: 9d2f67e43b73 ("net/packet: fix packet drop as of virtio gso") Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20211220145027.2784293-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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#
7e5cced9 |
| 20-Dec-2021 |
Willem de Bruijn <willemb@google.com> |
net: accept UFOv6 packages in virtio_net_hdr_to_skb
Skb with skb->protocol 0 at the time of virtio_net_hdr_to_skb may have a protocol inferred from virtio_net_hdr with virtio_net_hdr_set_proto.
Unl
net: accept UFOv6 packages in virtio_net_hdr_to_skb
Skb with skb->protocol 0 at the time of virtio_net_hdr_to_skb may have a protocol inferred from virtio_net_hdr with virtio_net_hdr_set_proto.
Unlike TCP, UDP does not have separate types for IPv4 and IPv6. Type VIRTIO_NET_HDR_GSO_UDP is guessed to be IPv4/UDP. As of the below commit, UFOv6 packets are dropped due to not matching the protocol as obtained from dev_parse_header_protocol.
Invert the test to take that L2 protocol field as starting point and pass both UFOv4 and UFOv6 for VIRTIO_NET_HDR_GSO_UDP.
Fixes: 924a9bc362a5 ("net: check if protocol extracted by virtio_net_hdr_set_proto is correct") Link: https://lore.kernel.org/netdev/CABcq3pG9GRCYqFDBAJ48H1vpnnX=41u+MhQnayF1ztLH4WX0Fw@mail.gmail.com/ Reported-by: Andrew Melnichenko <andrew@daynix.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20211220144901.2784030-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Revision tags: v5.15.10, v5.15.9, v5.15.8, v5.15.7, v5.15.6, v5.15.5, v5.15.4, v5.15.3 |
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#
cf9acc90 |
| 16-Nov-2021 |
Jonathan Davies <jonathan.davies@nutanix.com> |
net: virtio_net_hdr_to_skb: count transport header in UFO
virtio_net_hdr_to_skb does not set the skb's gso_size and gso_type correctly for UFO packets received via virtio-net that are a little over
net: virtio_net_hdr_to_skb: count transport header in UFO
virtio_net_hdr_to_skb does not set the skb's gso_size and gso_type correctly for UFO packets received via virtio-net that are a little over the GSO size. This can lead to problems elsewhere in the networking stack, e.g. ovs_vport_send dropping over-sized packets if gso_size is not set.
This is due to the comparison
if (skb->len - p_off > gso_size)
not properly accounting for the transport layer header.
p_off includes the size of the transport layer header (thlen), so skb->len - p_off is the size of the TCP/UDP payload.
gso_size is read from the virtio-net header. For UFO, fragmentation happens at the IP level so does not need to include the UDP header.
Hence the calculation could be comparing a TCP/UDP payload length with an IP payload length, causing legitimate virtio-net packets to have lack gso_type/gso_size information.
Example: a UDP packet with payload size 1473 has IP payload size 1481. If the guest used UFO, it is not fragmented and the virtio-net header's flags indicate that it is a GSO frame (VIRTIO_NET_HDR_GSO_UDP), with gso_size = 1480 for an MTU of 1500. skb->len will be 1515 and p_off will be 42, so skb->len - p_off = 1473. Hence the comparison fails, and shinfo->gso_size and gso_type are not set as they should be.
Instead, add the UDP header length before comparing to gso_size when using UFO. In this way, it is the size of the IP payload that is compared to gso_size.
Fixes: 6dd912f82680 ("net: check untrusted gso_size at kernel entry") Signed-off-by: Jonathan Davies <jonathan.davies@nutanix.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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#
b99c71f9 |
| 20-Dec-2021 |
Willem de Bruijn <willemb@google.com> |
net: skip virtio_net_hdr_set_proto if protocol already set
[ Upstream commit 1ed1d592113959f00cc552c3b9f47ca2d157768f ]
virtio_net_hdr_set_proto infers skb->protocol from the virtio_net_hdr gso_typ
net: skip virtio_net_hdr_set_proto if protocol already set
[ Upstream commit 1ed1d592113959f00cc552c3b9f47ca2d157768f ]
virtio_net_hdr_set_proto infers skb->protocol from the virtio_net_hdr gso_type, to avoid packets getting dropped for lack of a proto type.
Its protocol choice is a guess, especially in the case of UFO, where the single VIRTIO_NET_HDR_GSO_UDP label covers both UFOv4 and UFOv6.
Skip this best effort if the field is already initialized. Whether explicitly from userspace, or implicitly based on an earlier call to dev_parse_header_protocol (which is more robust, but was introduced after this patch).
Fixes: 9d2f67e43b73 ("net/packet: fix packet drop as of virtio gso") Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20211220145027.2784293-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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#
8ba353f5 |
| 20-Dec-2021 |
Willem de Bruijn <willemb@google.com> |
net: accept UFOv6 packages in virtio_net_hdr_to_skb
[ Upstream commit 7e5cced9ca84df52d874aca6b632f930b3dc5bc6 ]
Skb with skb->protocol 0 at the time of virtio_net_hdr_to_skb may have a protocol in
net: accept UFOv6 packages in virtio_net_hdr_to_skb
[ Upstream commit 7e5cced9ca84df52d874aca6b632f930b3dc5bc6 ]
Skb with skb->protocol 0 at the time of virtio_net_hdr_to_skb may have a protocol inferred from virtio_net_hdr with virtio_net_hdr_set_proto.
Unlike TCP, UDP does not have separate types for IPv4 and IPv6. Type VIRTIO_NET_HDR_GSO_UDP is guessed to be IPv4/UDP. As of the below commit, UFOv6 packets are dropped due to not matching the protocol as obtained from dev_parse_header_protocol.
Invert the test to take that L2 protocol field as starting point and pass both UFOv4 and UFOv6 for VIRTIO_NET_HDR_GSO_UDP.
Fixes: 924a9bc362a5 ("net: check if protocol extracted by virtio_net_hdr_set_proto is correct") Link: https://lore.kernel.org/netdev/CABcq3pG9GRCYqFDBAJ48H1vpnnX=41u+MhQnayF1ztLH4WX0Fw@mail.gmail.com/ Reported-by: Andrew Melnichenko <andrew@daynix.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20211220144901.2784030-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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#
0f810d06 |
| 16-Nov-2021 |
Jonathan Davies <jonathan.davies@nutanix.com> |
net: virtio_net_hdr_to_skb: count transport header in UFO
[ Upstream commit cf9acc90c80ecbee00334aa85d92f4e74014bcff ]
virtio_net_hdr_to_skb does not set the skb's gso_size and gso_type correctly f
net: virtio_net_hdr_to_skb: count transport header in UFO
[ Upstream commit cf9acc90c80ecbee00334aa85d92f4e74014bcff ]
virtio_net_hdr_to_skb does not set the skb's gso_size and gso_type correctly for UFO packets received via virtio-net that are a little over the GSO size. This can lead to problems elsewhere in the networking stack, e.g. ovs_vport_send dropping over-sized packets if gso_size is not set.
This is due to the comparison
if (skb->len - p_off > gso_size)
not properly accounting for the transport layer header.
p_off includes the size of the transport layer header (thlen), so skb->len - p_off is the size of the TCP/UDP payload.
gso_size is read from the virtio-net header. For UFO, fragmentation happens at the IP level so does not need to include the UDP header.
Hence the calculation could be comparing a TCP/UDP payload length with an IP payload length, causing legitimate virtio-net packets to have lack gso_type/gso_size information.
Example: a UDP packet with payload size 1473 has IP payload size 1481. If the guest used UFO, it is not fragmented and the virtio-net header's flags indicate that it is a GSO frame (VIRTIO_NET_HDR_GSO_UDP), with gso_size = 1480 for an MTU of 1500. skb->len will be 1515 and p_off will be 42, so skb->len - p_off = 1473. Hence the comparison fails, and shinfo->gso_size and gso_type are not set as they should be.
Instead, add the UDP header length before comparing to gso_size when using UFO. In this way, it is the size of the IP payload that is compared to gso_size.
Fixes: 6dd912f82680 ("net: check untrusted gso_size at kernel entry") Signed-off-by: Jonathan Davies <jonathan.davies@nutanix.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Revision tags: v5.15.2, v5.15.1, v5.15, v5.14.14, v5.14.13, v5.14.12, v5.14.11, v5.14.10, v5.14.9, v5.14.8, v5.14.7, v5.14.6, v5.10.67, v5.10.66, v5.14.5, v5.14.4, v5.10.65, v5.14.3, v5.10.64, v5.14.2, v5.10.63, v5.14.1, v5.10.62, v5.14, v5.10.61, v5.10.60, v5.10.53, v5.10.52, v5.10.51, v5.10.50, v5.10.49, v5.13, v5.10.46, v5.10.43, v5.10.42, v5.10.41, v5.10.40, v5.10.39, v5.4.119, v5.10.36, v5.10.35, v5.10.34, v5.4.116, v5.10.33, v5.12, v5.10.32, v5.10.31, v5.10.30 |
|
#
0f6925b3 |
| 02-Apr-2021 |
Eric Dumazet <edumazet@google.com> |
virtio_net: Do not pull payload in skb->head
Xuan Zhuo reported that commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for tiny skbs") brought a ~10% performance drop.
The reason for
virtio_net: Do not pull payload in skb->head
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 <xuanzhuo@linux.alibaba.com> Link: https://www.spinics.net/lists/netdev/msg731397.html Co-Developed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: virtualization@lists.linux-foundation.org Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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#
61431a59 |
| 30-Mar-2021 |
Eric Dumazet <edumazet@google.com> |
net: ensure mac header is set in virtio_net_hdr_to_skb()
Commit 924a9bc362a5 ("net: check if protocol extracted by virtio_net_hdr_set_proto is correct") added a call to dev_parse_header_protocol() b
net: ensure mac header is set in virtio_net_hdr_to_skb()
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 <edumazet@google.com> Cc: Balazs Nemeth <bnemeth@redhat.com> Cc: Willem de Bruijn <willemb@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v5.10.27, v5.10.26, v5.10.25, v5.10.24, v5.10.23 |
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#
924a9bc3 |
| 09-Mar-2021 |
Balazs Nemeth <bnemeth@redhat.com> |
net: check if protocol extracted by virtio_net_hdr_set_proto is correct
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
net: check if protocol extracted by virtio_net_hdr_set_proto is correct
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 <bnemeth@redhat.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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#
a36703d0 |
| 02-Apr-2021 |
Eric Dumazet <edumazet@google.com> |
virtio_net: Do not pull payload in skb->head
[ Upstream commit 0f6925b3e8da0dbbb52447ca8a8b42b371aac7db ]
Xuan Zhuo reported that commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for
virtio_net: Do not pull payload in skb->head
[ 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 <xuanzhuo@linux.alibaba.com> Link: https://www.spinics.net/lists/netdev/msg731397.html Co-Developed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: virtualization@lists.linux-foundation.org Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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#
f0b4c9ac |
| 30-Mar-2021 |
Eric Dumazet <edumazet@google.com> |
net: ensure mac header is set in virtio_net_hdr_to_skb()
commit 61431a5907fc36d0738e9a547c7e1556349a03e9 upstream.
Commit 924a9bc362a5 ("net: check if protocol extracted by virtio_net_hdr_set_proto
net: ensure mac header is set in virtio_net_hdr_to_skb()
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 <edumazet@google.com> Cc: Balazs Nemeth <bnemeth@redhat.com> Cc: Willem de Bruijn <willemb@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
faa3baa2 |
| 09-Mar-2021 |
Balazs Nemeth <bnemeth@redhat.com> |
net: check if protocol extracted by virtio_net_hdr_set_proto is correct
commit 924a9bc362a5223cd448ca08c3dde21235adc310 upstream.
For gso packets, virtio_net_hdr_set_proto sets the protocol (if it
net: check if protocol extracted by virtio_net_hdr_set_proto is correct
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 <bnemeth@redhat.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Revision tags: v5.10.22, v5.10.21, v5.10.20, v5.10.19, v5.4.101, v5.10.18, v5.10.17, v5.11, v5.10.16, v5.10.15, v5.10.14, v5.10, v5.8.17, v5.8.16, v5.8.15, v5.9, v5.8.14, v5.8.13, v5.8.12, v5.8.11, v5.8.10, v5.8.9, v5.8.8, v5.8.7, v5.8.6, v5.4.62, v5.8.5, v5.8.4, v5.4.61, v5.8.3, v5.4.60, v5.8.2, v5.4.59, v5.8.1, v5.4.58, v5.4.57, v5.4.56, v5.8, v5.7.12, v5.4.55, v5.7.11, v5.4.54, v5.7.10, v5.4.53, v5.4.52, v5.7.9, v5.7.8, v5.4.51, v5.4.50, v5.7.7, v5.4.49, v5.7.6, v5.7.5, v5.4.48, v5.7.4, v5.7.3, v5.4.47, v5.4.46, v5.7.2, v5.4.45, v5.7.1, v5.4.44, v5.7 |
|
#
7c6d2ecb |
| 28-May-2020 |
Eric Dumazet <edumazet@google.com> |
net: be more gentle about silly gso requests coming from user
Recent change in virtio_net_hdr_to_skb() broke some packetdrill tests.
When --mss=XXX option is set, packetdrill always provide gso_typ
net: be more gentle about silly gso requests coming from user
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 <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v5.4.43 |
|
#
6dd912f8 |
| 25-May-2020 |
Willem de Bruijn <willemb@google.com> |
net: check untrusted gso_size at kernel entry
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_segmen
net: check untrusted gso_size at kernel entry
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 <syzkaller@googlegroups.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v5.4.42, v5.4.41, v5.4.40, v5.4.39 |
|
#
9274124f |
| 04-May-2020 |
Willem de Bruijn <willemb@google.com> |
net: stricter validation of untrusted gso packets
Syzkaller again found a path to a kernel crash through bad gso input: a packet with transport header extending beyond skb_headlen(skb).
Tighten val
net: stricter validation of untrusted gso packets
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 <syzkaller@googlegroups.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v5.4.38, v5.4.37, v5.4.36, v5.4.35, v5.4.34, v5.4.33, v5.4.32, v5.4.31, v5.4.30, v5.4.29, v5.6, v5.4.28, v5.4.27, v5.4.26, v5.4.25, v5.4.24, v5.4.23, v5.4.22, v5.4.21, v5.4.20, v5.4.19, v5.4.18, v5.4.17, v5.4.16, v5.5, v5.4.15, v5.4.14, v5.4.13, v5.4.12, v5.4.11, v5.4.10, v5.4.9, v5.4.8, v5.4.7, v5.4.6, v5.4.5, v5.4.4, v5.4.3, v5.3.15, v5.4.2, v5.4.1, v5.3.14, v5.4, v5.3.13, v5.3.12, v5.3.11, v5.3.10, v5.3.9, v5.3.8, v5.3.7, v5.3.6, v5.3.5, v5.3.4, v5.3.3, v5.3.2, v5.3.1, v5.3, v5.2.14, v5.3-rc8, v5.2.13, v5.2.12, v5.2.11, v5.2.10, v5.2.9, v5.2.8, v5.2.7, v5.2.6, v5.2.5, v5.2.4, v5.2.3, v5.2.2, v5.2.1, v5.2, v5.1.16, v5.1.15, v5.1.14, v5.1.13, v5.1.12, v5.1.11, v5.1.10, v5.1.9, v5.1.8, v5.1.7, v5.1.6, v5.1.5, v5.1.4, v5.1.3, v5.1.2, v5.1.1, v5.0.14, v5.1, v5.0.13, v5.0.12, v5.0.11, v5.0.10, v5.0.9, v5.0.8, v5.0.7, v5.0.6, v5.0.5, v5.0.4, v5.0.3, v4.19.29, v5.0.2, v4.19.28, v5.0.1, v4.19.27, v5.0, v4.19.26, v4.19.25 |
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#
d2aa125d |
| 21-Feb-2019 |
Maxim Mikityanskiy <maximmi@mellanox.com> |
net: Don't set transport offset to invalid value
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_h
net: Don't set transport offset to invalid value
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 <maximmi@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v4.19.24 |
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#
9e8db591 |
| 18-Feb-2019 |
Willem de Bruijn <willemb@google.com> |
net: avoid false positives in untrusted gso validation
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
net: avoid false positives in untrusted gso validation
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 <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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d5be7f63 |
| 15-Feb-2019 |
Willem de Bruijn <willemb@google.com> |
net: validate untrusted gso packets without csum offload
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.
net: validate untrusted gso packets without csum offload
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 <syzkaller@googlegroups.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v4.19.23, v4.19.22, v4.19.21, v4.19.20, v4.19.19, v4.19.18, v4.19.17, v4.19.16, v4.19.15, v4.19.14, v4.19.13, v4.19.12, v4.19.11, v4.19.10, v4.19.9, v4.19.8, v4.19.7, v4.19.6, v4.19.5, v4.19.4, v4.18.20, v4.19.3, v4.18.19, v4.19.2, v4.18.18, v4.18.17, v4.19.1, v4.19, v4.18.16, v4.18.15, v4.18.14, v4.18.13, v4.18.12 |
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9d2f67e4 |
| 29-Sep-2018 |
Jianfeng Tan <jianfeng.tan@linux.alibaba.com> |
net/packet: fix packet drop as of virtio gso
When we use raw socket as the vhost backend, a packet from virito with gso offloading information, cannot be sent out in later validaton at xmit path, as
net/packet: fix packet drop as of virtio gso
When we use raw socket as the vhost backend, a packet from virito with gso offloading information, cannot be sent out in later validaton at xmit path, as we did not set correct skb->protocol which is further used for looking up the gso function.
To fix this, we set this field according to virito hdr information.
Fixes: e858fae2b0b8f4 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion") Signed-off-by: Jianfeng Tan <jianfeng.tan@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v4.18.11, v4.18.10, v4.18.9, v4.18.7, v4.18.6, v4.18.5, v4.17.18, v4.18.4, v4.18.3, v4.17.17, v4.18.2, v4.17.16, v4.17.15, v4.18.1, v4.18, v4.17.14, v4.17.13, v4.17.12, v4.17.11, v4.17.10, v4.17.9, v4.17.8, v4.17.7, v4.17.6, v4.17.5, v4.17.4, v4.17.3, v4.17.2, v4.17.1 |
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fd3a8862 |
| 06-Jun-2018 |
Willem de Bruijn <willemb@google.com> |
net: in virtio_net_hdr only add VLAN_HLEN to csum_start if payload holds vlan
Tun, tap, virtio, packet and uml vector all use struct virtio_net_hdr to communicate packet metadata to userspace.
For
net: in virtio_net_hdr only add VLAN_HLEN to csum_start if payload holds vlan
Tun, tap, virtio, packet and uml vector all use struct virtio_net_hdr to communicate packet metadata to userspace.
For skbuffs with vlan, the first two return the packet as it may have existed on the wire, inserting the VLAN tag in the user buffer. Then virtio_net_hdr.csum_start needs to be adjusted by VLAN_HLEN bytes.
Commit f09e2249c4f5 ("macvtap: restore vlan header on user read") added this feature to macvtap. Commit 3ce9b20f1971 ("macvtap: Fix csum_start when VLAN tags are present") then fixed up csum_start.
Virtio, packet and uml do not insert the vlan header in the user buffer.
When introducing virtio_net_hdr_from_skb to deduplicate filling in the virtio_net_hdr, the variant from macvtap which adds VLAN_HLEN was applied uniformly, breaking csum offset for packets with vlan on virtio and packet.
Make insertion of VLAN_HLEN optional. Convert the callers to pass it when needed.
Fixes: e858fae2b0b8f4 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion") Fixes: 1276f24eeef2 ("packet: use common code for virtio_net_hdr and skb GSO conversion") Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Revision tags: v4.17, v4.16, v4.15, v4.13.16 |
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0c19f846 |
| 21-Nov-2017 |
Willem de Bruijn <willemb@google.com> |
net: accept UFO datagrams from tuntap and packet
Tuntap and similar devices can inject GSO packets. Accept type VIRTIO_NET_HDR_GSO_UDP, even though not generating UFO natively.
Processes are expect
net: accept UFO datagrams from tuntap and packet
Tuntap and similar devices can inject GSO packets. Accept type VIRTIO_NET_HDR_GSO_UDP, even though not generating UFO natively.
Processes are expected to use feature negotiation such as TUNSETOFFLOAD to detect supported offload types and refrain from injecting other packets. This process breaks down with live migration: guest kernels do not renegotiate flags, so destination hosts need to expose all features that the source host does.
Partially revert the UFO removal from 182e0b6b5846~1..d9d30adf5677. This patch introduces nearly(*) no new code to simplify verification. It brings back verbatim tuntap UFO negotiation, VIRTIO_NET_HDR_GSO_UDP insertion and software UFO segmentation.
It does not reinstate protocol stack support, hardware offload (NETIF_F_UFO), SKB_GSO_UDP tunneling in SKB_GSO_SOFTWARE or reception of VIRTIO_NET_HDR_GSO_UDP packets in tuntap.
To support SKB_GSO_UDP reappearing in the stack, also reinstate logic in act_csum and openvswitch. Achieve equivalence with v4.13 HEAD by squashing in commit 939912216fa8 ("net: skb_needs_check() removes CHECKSUM_UNNECESSARY check for tx.") and reverting commit 8d63bee643f1 ("net: avoid skb_warn_bad_offload false positives on UFO").
(*) To avoid having to bring back skb_shinfo(skb)->ip6_frag_id, ipv6_proxy_select_ident is changed to return a __be32 and this is assigned directly to the frag_hdr. Also, SKB_GSO_UDP is inserted at the end of the enum to minimize code churn.
Tested Booted a v4.13 guest kernel with QEMU. On a host kernel before this patch `ethtool -k eth0` shows UFO disabled. After the patch, it is enabled, same as on a v4.13 host kernel.
A UFO packet sent from the guest appears on the tap device: host: nc -l -p -u 8000 & tcpdump -n -i tap0
guest: dd if=/dev/zero of=payload.txt bs=1 count=2000 nc -u 192.16.1.1 8000 < payload.txt
Direct tap to tap transmission of VIRTIO_NET_HDR_GSO_UDP succeeds, packets arriving fragmented:
./with_tap_pair.sh ./tap_send_ufo tap0 tap1 (from https://github.com/wdebruij/kerneltools/tree/master/tests)
Changes v1 -> v2 - simplified set_offload change (review comment) - documented test procedure
Link: http://lkml.kernel.org/r/<CAF=yD-LuUeDuL9YWPJD9ykOZ0QCjNeznPDr6whqZ9NGMNF12Mw@mail.gmail.com> Fixes: fb652fdfe837 ("macvlan/macvtap: Remove NETIF_F_UFO advertisement.") Reported-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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