As the call trace shows, skb_panic was caused by wrong skb->mac_header
in nsh_gso_segment():
invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 3 PID: 2737 Comm: syz Not tainted 6.3.0-next-20230505 #1
RIP: 0010:skb_panic+0xda/0xe0
call Trace:
skb_push+0x91/0xa0
nsh_gso_segment+0x4f3/0x570
skb_mac_gso_segment+0x19e/0x270
__skb_gso_segment+0x1e8/0x3c0
validate_xmit_skb+0x452/0x890
validate_xmit_skb_list+0x99/0xd0
sch_direct_xmit+0x294/0x7c0
__dev_queue_xmit+0x16f0/0x1d70
packet_xmit+0x185/0x210
packet_snd+0xc15/0x1170
packet_sendmsg+0x7b/0xa0
sock_sendmsg+0x14f/0x160
The root cause is:
nsh_gso_segment() use skb->network_header - nhoff to reset mac_header
in skb_gso_error_unwind() if inner-layer protocol gso fails.
However, skb->network_header may be reset by inner-layer protocol
gso function e.g. mpls_gso_segment. skb->mac_header reset by the
inaccurate network_header will be larger than skb headroom.
nsh_gso_segment
nhoff = skb->network_header - skb->mac_header;
__skb_pull(skb,nsh_len)
skb_mac_gso_segment
mpls_gso_segment
skb_reset_network_header(skb);//skb->network_header+=nsh_len
return -EINVAL;
skb_gso_error_unwind
skb_push(skb, nsh_len);
skb->mac_header = skb->network_header - nhoff;
// skb->mac_header > skb->headroom, cause skb_push panic
Use correct mac_offset to restore mac_header and get rid of nhoff.
Fixes: c411ed8545 ("nsh: add GSO support")
Reported-by: syzbot+632b5d9964208bfef8c0@syzkaller.appspotmail.com
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When pulling the NSH header in nsh_gso_segment, set the mac length
based on the encapsulated packet type.
skb_reset_mac_len computes an offset to the network header, which
here still points to the outer packet:
> skb_reset_network_header(skb);
> [...]
> __skb_pull(skb, nsh_len);
> skb_reset_mac_header(skb); // now mac hdr starts nsh_len == 8B after net hdr
> skb_reset_mac_len(skb); // mac len = net hdr - mac hdr == (u16) -8 == 65528
> [..]
> skb_mac_gso_segment(skb, ..)
Link: http://lkml.kernel.org/r/CAF=yD-KeAcTSOn4AxirAxL8m7QAS8GBBe1w09eziYwvPbbUeYA@mail.gmail.com
Reported-by: syzbot+7b9ed9872dab8c32305d@syzkaller.appspotmail.com
Fixes: c411ed8545 ("nsh: add GSO support")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
v16->17
- Fixed disputed check code: keep them in nsh_push and nsh_pop
but also add them in __ovs_nla_copy_actions
v15->v16
- Add csum recalculation for nsh_push, nsh_pop and set_nsh
pointed out by Pravin
- Move nsh key into the union with ipv4 and ipv6 and add
check for nsh key in match_validate pointed out by Pravin
- Add nsh check in validate_set and __ovs_nla_copy_actions
v14->v15
- Check size in nsh_hdr_from_nlattr
- Fixed four small issues pointed out By Jiri and Eric
v13->v14
- Rename skb_push_nsh to nsh_push per Dave's comment
- Rename skb_pop_nsh to nsh_pop per Dave's comment
v12->v13
- Fix NSH header length check in set_nsh
v11->v12
- Fix missing changes old comments pointed out
- Fix new comments for v11
v10->v11
- Fix the left three disputable comments for v9
but not fixed in v10.
v9->v10
- Change struct ovs_key_nsh to
struct ovs_nsh_key_base base;
__be32 context[NSH_MD1_CONTEXT_SIZE];
- Fix new comments for v9
v8->v9
- Fix build error reported by daily intel build
because nsh module isn't selected by openvswitch
v7->v8
- Rework nested value and mask for OVS_KEY_ATTR_NSH
- Change pop_nsh to adapt to nsh kernel module
- Fix many issues per comments from Jiri Benc
v6->v7
- Remove NSH GSO patches in v6 because Jiri Benc
reworked it as another patch series and they have
been merged.
- Change it to adapt to nsh kernel module added by NSH
GSO patch series
v5->v6
- Fix the rest comments for v4.
- Add NSH GSO support for VxLAN-gpe + NSH and
Eth + NSH.
v4->v5
- Fix many comments by Jiri Benc and Eric Garver
for v4.
v3->v4
- Add new NSH match field ttl
- Update NSH header to the latest format
which will be final format and won't change
per its author's confirmation.
- Fix comments for v3.
v2->v3
- Change OVS_KEY_ATTR_NSH to nested key to handle
length-fixed attributes and length-variable
attriubte more flexibly.
- Remove struct ovs_action_push_nsh completely
- Add code to handle nested attribute for SET_MASKED
- Change PUSH_NSH to use the nested OVS_KEY_ATTR_NSH
to transfer NSH header data.
- Fix comments and coding style issues by Jiri and Eric
v1->v2
- Change encap_nsh and decap_nsh to push_nsh and pop_nsh
- Dynamically allocate struct ovs_action_push_nsh for
length-variable metadata.
OVS master and 2.8 branch has merged NSH userspace
patch series, this patch is to enable NSH support
in kernel data path in order that OVS can support
NSH in compat mode by porting this.
Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Eric Garver <e@erig.me>
Acked-by: Pravin Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new nsh/ directory. It currently holds only GSO functions but more
will come: in particular, code shared by openvswitch and tc to manipulate
NSH headers.
For now, assume there's no hardware support for NSH segmentation. We can
always introduce netdev->nsh_features later.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>