[syzbot] [net?] general protection fault in veth_xdp_rcv

Mon Jun 2 13:21:34 UTC 2025

Hello,

syzbot found the following issue on:

HEAD commit:    4cb6c8af8591 selftests/filesystems: Fix build of anon_inod..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11e8300c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5319177d225a42f1
dashboard link: https://syzkaller.appspot.com/bug?extid=c4c7bf27f6b0c4bd97fe
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-4cb6c8af.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bc0e5dfdd686/vmlinux-4cb6c8af.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2cdd323de6ca/bzImage-4cb6c8af.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c4c7bf27f6b0c4bd97fe at syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000098: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000004c0-0x00000000000004c7]
CPU: 1 UID: 0 PID: 5975 Comm: kworker/1:4 Not tainted 6.15.0-syzkaller-10402-g4cb6c8af8591 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker
RIP: 0010:netdev_get_tx_queue include/linux/netdevice.h:2636 [inline]
RIP: 0010:veth_xdp_rcv.constprop.0+0x142/0xda0 drivers/net/veth.c:912
Code: 54 d9 31 fb 45 85 e4 0f 85 db 08 00 00 e8 06 de 31 fb 48 8d bd c0 04 00 00 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 18 0c 00 00 44 8b a5 c0 04 00
RSP: 0018:ffffc900006a09b8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff868a1686
RDX: 0000000000000098 RSI: ffffffff868a0d9a RDI: 00000000000004c0
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffffc900006a0ff8 R12: 0000000000000001
R13: 1ffff920000d4145 R14: ffffc900006a0e58 R15: ffff8880503d0000
FS:  0000000000000000(0000) GS:ffff8880d686e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe5e3a6ad58 CR3: 000000000e382000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 veth_poll+0x19c/0x9c0 drivers/net/veth.c:979
 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
 do_softirq kernel/softirq.c:480 [inline]
 do_softirq+0xb2/0xf0 kernel/softirq.c:467
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline]
 kernel_fpu_end+0x5e/0x70 arch/x86/kernel/fpu/core.c:476
 blake2s_compress+0x7f/0xe0 arch/x86/lib/crypto/blake2s-glue.c:46
 blake2s_final+0xc9/0x150 lib/crypto/blake2s.c:54
 hmac.constprop.0+0x335/0x420 drivers/net/wireguard/noise.c:333
 kdf.constprop.0+0x122/0x280 drivers/net/wireguard/noise.c:360
 mix_dh+0xe8/0x150 drivers/net/wireguard/noise.c:413
 wg_noise_handshake_consume_initiation+0x265/0x880 drivers/net/wireguard/noise.c:608
 wg_receive_handshake_packet+0x219/0xbf0 drivers/net/wireguard/receive.c:144
 wg_packet_handshake_receive_worker+0x17f/0x3a0 drivers/net/wireguard/receive.c:213
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:netdev_get_tx_queue include/linux/netdevice.h:2636 [inline]
RIP: 0010:veth_xdp_rcv.constprop.0+0x142/0xda0 drivers/net/veth.c:912
Code: 54 d9 31 fb 45 85 e4 0f 85 db 08 00 00 e8 06 de 31 fb 48 8d bd c0 04 00 00 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 18 0c 00 00 44 8b a5 c0 04 00
RSP: 0018:ffffc900006a09b8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff868a1686
RDX: 0000000000000098 RSI: ffffffff868a0d9a RDI: 00000000000004c0
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffffc900006a0ff8 R12: 0000000000000001
R13: 1ffff920000d4145 R14: ffffc900006a0e58 R15: ffff8880503d0000
FS:  0000000000000000(0000) GS:ffff8880d686e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe5e3a6ad58 CR3: 000000000e382000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	54                   	push   %rsp
   1:	d9 31                	fnstenv (%rcx)
   3:	fb                   	sti
   4:	45 85 e4             	test   %r12d,%r12d
   7:	0f 85 db 08 00 00    	jne    0x8e8
   d:	e8 06 de 31 fb       	call   0xfb31de18
  12:	48 8d bd c0 04 00 00 	lea    0x4c0(%rbp),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	74 08                	je     0x3a
  32:	3c 03                	cmp    $0x3,%al
  34:	0f 8e 18 0c 00 00    	jle    0xc52
  3a:	44                   	rex.R
  3b:	8b                   	.byte 0x8b
  3c:	a5                   	movsl  %ds:(%rsi),%es:(%rdi)
  3d:	c0                   	.byte 0xc0
  3e:	04 00                	add    $0x0,%al

---
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