syzbot


general protection fault in arp_netdev_event

Status: closed as invalid on 2025/07/02 15:51
Subsystems: net
[Documentation on labels]
First crash: 87d, last: 87d

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000021: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
CPU: 1 UID: 0 PID: 15749 Comm: syz.2.2512 Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #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
RIP: 0010:read_pnet include/net/net_namespace.h:409 [inline]
RIP: 0010:dev_net include/linux/netdevice.h:2713 [inline]
RIP: 0010:arp_netdev_event+0x180/0x3c0 net/ipv4/arp.c:1342
Code: 80 3c 02 00 0f 85 22 02 00 00 48 8b 2b e8 38 91 84 01 48 b8 00 00 00 00 00 fc ff df 48 8d bd 08 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 1c 02 00 00 48 8b ad 08 01 00 00 48 b8 00 00 00
RSP: 0000:ffffc90004506f30 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88804d16bc00 RCX: ffffc90028e96000
RDX: 0000000000000021 RSI: ffffffff89f50055 RDI: 0000000000000108
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880238dc000
R13: dffffc0000000000 R14: ffffffff902bf660 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888097875000(0063) knlGS:00000000f50bcb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080019680 CR3: 00000000695b9000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
 netif_state_change+0x165/0x3b0 net/core/dev.c:1584
 do_setlink.constprop.0+0x3570/0x4380 net/core/rtnetlink.c:3388
 rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
 rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
 __sys_sendmsg+0x16d/0x220 net/socket.c:2652
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf710e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f50bc55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000080000280
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:read_pnet include/net/net_namespace.h:409 [inline]
RIP: 0010:dev_net include/linux/netdevice.h:2713 [inline]
RIP: 0010:arp_netdev_event+0x180/0x3c0 net/ipv4/arp.c:1342
Code: 80 3c 02 00 0f 85 22 02 00 00 48 8b 2b e8 38 91 84 01 48 b8 00 00 00 00 00 fc ff df 48 8d bd 08 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 1c 02 00 00 48 8b ad 08 01 00 00 48 b8 00 00 00
RSP: 0000:ffffc90004506f30 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88804d16bc00 RCX: ffffc90028e96000
RDX: 0000000000000021 RSI: ffffffff89f50055 RDI: 0000000000000108
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880238dc000
R13: dffffc0000000000 R14: ffffffff902bf660 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888097875000(0063) knlGS:00000000f50bcb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080019680 CR3: 00000000695b9000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   4:	0f 85 22 02 00 00    	jne    0x22c
   a:	48 8b 2b             	mov    (%rbx),%rbp
   d:	e8 38 91 84 01       	call   0x184914a
  12:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  19:	fc ff df
  1c:	48 8d bd 08 01 00 00 	lea    0x108(%rbp),%rdi
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 1c 02 00 00    	jne    0x250
  34:	48 8b ad 08 01 00 00 	mov    0x108(%rbp),%rbp
  3b:	48                   	rex.W
  3c:	b8                   	.byte 0xb8
  3d:	00 00                	add    %al,(%rax)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/01 20:30 upstream 7d4e49a77d99 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in arp_netdev_event
* Struck through repros no longer work on HEAD.