syzbot


general protection fault in sit_exit_rtnl_net

Status: closed as invalid on 2025/09/16 17:45
Subsystems: net
[Documentation on labels]
First crash: 51d, last: 51d

Sample crash report:
netdevsim netdevsim4 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim4 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim4 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
Oops: general protection fault, probably for non-canonical address 0xdffffc001fffe003: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x00000000ffff0018-0x00000000ffff001f]
CPU: 0 UID: 0 PID: 6874 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: netns cleanup_net
RIP: 0010:sit_exit_rtnl_net+0x20f/0x380 net/ipv6/sit.c:1827
Code: 4c 89 ff e8 23 26 db f7 4d 8b 3f 4d 85 ff 75 0f e8 46 ba 77 f7 e9 16 01 00 00 e8 3c ba 77 f7 49 8d 5f 18 49 89 dc 49 c1 ec 03 <41> 80 3c 2c 00 74 08 48 89 df e8 f2 25 db f7 4c 8b 2b b8 08 01 00
RSP: 0000:ffffc90019a6f878 EFLAGS: 00010206
RAX: 1ffff1100bfa1b85 RBX: 00000000ffff0018 RCX: ffff88802278bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff8f5382a7 R09: 1ffffffff1ea7054
R10: dffffc0000000000 R11: fffffbfff1ea7055 R12: 000000001fffe003
R13: ffff88802af6c108 R14: ffff888029414880 R15: 00000000ffff0000
FS:  0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2da10ff8 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ops_exit_rtnl_list net/core/net_namespace.c:180 [inline]
 ops_undo_list+0x350/0x990 net/core/net_namespace.c:247
 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 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:sit_exit_rtnl_net+0x20f/0x380 net/ipv6/sit.c:1827
Code: 4c 89 ff e8 23 26 db f7 4d 8b 3f 4d 85 ff 75 0f e8 46 ba 77 f7 e9 16 01 00 00 e8 3c ba 77 f7 49 8d 5f 18 49 89 dc 49 c1 ec 03 <41> 80 3c 2c 00 74 08 48 89 df e8 f2 25 db f7 4c 8b 2b b8 08 01 00
RSP: 0000:ffffc90019a6f878 EFLAGS: 00010206
RAX: 1ffff1100bfa1b85 RBX: 00000000ffff0018 RCX: ffff88802278bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff8f5382a7 R09: 1ffffffff1ea7054
R10: dffffc0000000000 R11: fffffbfff1ea7055 R12: 000000001fffe003
R13: ffff88802af6c108 R14: ffff888029414880 R15: 00000000ffff0000
FS:  0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2da10ff8 CR3: 000000000df36000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	4c 89 ff             	mov    %r15,%rdi
   3:	e8 23 26 db f7       	call   0xf7db262b
   8:	4d 8b 3f             	mov    (%r15),%r15
   b:	4d 85 ff             	test   %r15,%r15
   e:	75 0f                	jne    0x1f
  10:	e8 46 ba 77 f7       	call   0xf777ba5b
  15:	e9 16 01 00 00       	jmp    0x130
  1a:	e8 3c ba 77 f7       	call   0xf777ba5b
  1f:	49 8d 5f 18          	lea    0x18(%r15),%rbx
  23:	49 89 dc             	mov    %rbx,%r12
  26:	49 c1 ec 03          	shr    $0x3,%r12
* 2a:	41 80 3c 2c 00       	cmpb   $0x0,(%r12,%rbp,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 f2 25 db f7       	call   0xf7db262b
  39:	4c 8b 2b             	mov    (%rbx),%r13
  3c:	b8                   	.byte 0xb8
  3d:	08 01                	or     %al,(%rcx)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/23 18:33 net-next b1c92cdf5af3 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce general protection fault in sit_exit_rtnl_net
* Struck through repros no longer work on HEAD.