------------[ cut here ]------------
WARNING: CPU: 0 PID: 5882 at net/ipv4/ipmr.c:2302 ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302
Modules linked in:
CPU: 0 UID: 0 PID: 5882 Comm: napi/wg0-0 Not tainted 6.16.0-rc2-syzkaller-00591-g4f4040ea5d3e #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302
Code: df e9 63 f6 ff ff e8 ce 33 c6 f7 48 8b 74 24 18 45 31 f6 31 ff ba 02 00 00 00 e8 9a 09 4c ff e9 45 f6 ff ff e8 b0 33 c6 f7 90 <0f> 0b 90 e9 94 f5 ff ff e8 a2 33 c6 f7 90 0f 0b 90 42 80 3c 2b 00
RSP: 0018:ffffc90000007900 EFLAGS: 00010246
RAX: ffffffff89fa28a0 RBX: ffff8880290cb3c0 RCX: ffff88802f249e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007a10 R08: ffff88802f249e00 R09: 0000000000000004
R10: 0000000000000003 R11: ffffffff89fa1cf0 R12: 0000000000000010
R13: dffffc0000000000 R14: ffff88802fc51000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125c4f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3041aff8 CR3: 000000006ba10000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 igmp_send_report+0x89e/0xdb0 net/ipv4/igmp.c:799
 igmp_timer_expire+0x204/0x510 net/ipv4/igmp.c:-1
 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:stack_not_used kernel/exit.c:797 [inline]
RIP: 0010:check_stack_usage kernel/exit.c:849 [inline]
RIP: 0010:do_exit+0x1856/0x22e0 kernel/exit.c:998
Code: e8 03 42 80 3c 20 00 74 08 48 89 df e8 d3 d5 9e 00 4c 8b 3b bb 08 00 00 00 41 be f8 7f 00 00 49 8d 3c 1f 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 ae d5 9e 00 49 83 3c 1f 00 75 0f e8 82 57
RSP: 0018:ffffc900043dfc00 EFLAGS: 00000a06
RAX: 1ffff9200087b3e4 RBX: 0000000000001f20 RCX: ffff88802f249e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900043d9f20
RBP: ffffc900043dfd58 R08: ffffffff8fa11ff7 R09: 1ffffffff1f423fe
R10: dffffc0000000000 R11: fffffbfff1f423ff R12: dffffc0000000000
R13: 1ffff11005e49486 R14: 00000000000060e0 R15: ffffc900043d8000
 kthread_exit+0x22c/0x280 kernel/kthread.c:337
 kthread+0x72f/0x8a0 kernel/kthread.c:466
 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>
----------------
Code disassembly (best guess):
   0:	e8 03 42 80 3c       	call   0x3c804208
   5:	20 00                	and    %al,(%rax)
   7:	74 08                	je     0x11
   9:	48 89 df             	mov    %rbx,%rdi
   c:	e8 d3 d5 9e 00       	call   0x9ed5e4
  11:	4c 8b 3b             	mov    (%rbx),%r15
  14:	bb 08 00 00 00       	mov    $0x8,%ebx
  19:	41 be f8 7f 00 00    	mov    $0x7ff8,%r14d
  1f:	49 8d 3c 1f          	lea    (%r15,%rbx,1),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 ae d5 9e 00       	call   0x9ed5e4
  36:	49 83 3c 1f 00       	cmpq   $0x0,(%r15,%rbx,1)
  3b:	75 0f                	jne    0x4c
  3d:	e8                   	.byte 0xe8
  3e:	82                   	(bad)
  3f:	57                   	push   %rdi