syzbot


WARNING in ip6erspan_tunnel_xmit (2)

Status: fixed on 2023/06/08 14:41
Subsystems: net
[Documentation on labels]
Fix commit: 8e50ed774554 erspan: do not use skb_mac_header() in ndo_start_xmit()
First crash: 424d, last: 424d
Cause bisection: introduced by (bisect log) [merge commit]:
commit be1a63daffdd152ba4c7b71ab9fec2e39259b42b
Author: Mark Brown <broonie@kernel.org>
Date: Mon Jun 6 11:32:40 2022 +0000

  Merge existing fixes from asoc/for-5.19 into new branch

Crash: WARNING in ipgre_xmit (log)
Repro: C syz .config
  
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in ip6erspan_tunnel_xmit net 23 455d 700d 22/26 fixed on 2023/02/24 13:50
linux-6.1 WARNING in ip6erspan_tunnel_xmit C done 1 423d 423d 3/3 fixed on 2023/04/20 22:24

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5080 at include/linux/skbuff.h:2875 skb_mac_header include/linux/skbuff.h:2875 [inline]
WARNING: CPU: 1 PID: 5080 at include/linux/skbuff.h:2875 ip6erspan_tunnel_xmit+0x1d9c/0x2d90 net/ipv6/ip6_gre.c:962
Modules linked in:
CPU: 1 PID: 5080 Comm: syz-executor424 Not tainted 6.3.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
RIP: 0010:skb_mac_header include/linux/skbuff.h:2875 [inline]
RIP: 0010:ip6erspan_tunnel_xmit+0x1d9c/0x2d90 net/ipv6/ip6_gre.c:962
Code: 04 02 41 01 de 84 c0 74 08 3c 03 0f 8e 1c 0a 00 00 45 89 b4 24 c8 00 00 00 c6 85 77 fe ff ff 01 e9 33 e7 ff ff e8 d4 f0 a2 f8 <0f> 0b e9 b6 e7 ff ff e8 c8 f0 a2 f8 49 8d bf f0 0c 00 00 48 b8 00
RSP: 0018:ffffc90003d9f838 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000000000ffff RCX: 0000000000000000
RDX: ffff8880248b0000 RSI: ffffffff88dff42c RDI: 0000000000000003
RBP: ffffc90003d9f9e0 R08: 0000000000000003 R09: 000000000000ffff
R10: 000000000000ffff R11: 0000000000000000 R12: ffff8880292c8c80
R13: 00000000000000d0 R14: ffff88802a83ded0 R15: ffff88802236a000
FS:  0000555557036300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc0bed8dd0 CR3: 0000000029a50000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __netdev_start_xmit include/linux/netdevice.h:4883 [inline]
 netdev_start_xmit include/linux/netdevice.h:4897 [inline]
 __dev_direct_xmit+0x504/0x730 net/core/dev.c:4302
 dev_direct_xmit include/linux/netdevice.h:3066 [inline]
 packet_direct_xmit+0x1b7/0x310 net/packet/af_packet.c:282
 packet_snd net/packet/af_packet.c:3073 [inline]
 packet_sendmsg+0x33aa/0x55d0 net/packet/af_packet.c:3104
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:747
 __sys_sendto+0x23a/0x340 net/socket.c:2142
 __do_sys_sendto net/socket.c:2154 [inline]
 __se_sys_sendto net/socket.c:2150 [inline]
 __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2150
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5b7afde039
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff92039f78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b7afde039
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000020000040 R09: 0000000000000014
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5b7afa18c0
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/20 15:33 upstream e8d018dd0257 7939252e .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in ip6erspan_tunnel_xmit
2023/03/20 19:12 net f36fa5581bca 7939252e .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ip6erspan_tunnel_xmit
2023/03/20 13:33 net-next d4671cb96fa3 7939252e .config strace log report syz C ci-upstream-net-kasan-gce WARNING in ip6erspan_tunnel_xmit
2023/03/20 14:16 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in ip6erspan_tunnel_xmit
2023/03/20 12:05 net-next d4671cb96fa3 7939252e .config console log report info ci-upstream-net-kasan-gce WARNING in ip6erspan_tunnel_xmit
* Struck through repros no longer work on HEAD.