Kernel bug: WARNING in ip_mr_output
Subsystem: netfilter
Status: fixed

Crash report:
WARNING: CPU: 0 PID: 5859 at net/ipv4/ipmr.c:2302 ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302
Modules linked in:
CPU: 0 UID: 0 PID: 5859 Comm: syz-executor357 Not tainted 6.16.0-rc1-syzkaller-00413-gfc4842cd0f11 #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 8e 72 c6 f7 48 8b 74 24 18 45 31 f6 31 ff ba 02 00 00 00 e8 ea 14 4c ff e9 45 f6 ff ff e8 70 72 c6 f7 90 <0f> 0b 90 e9 94 f5 ff ff e8 62 72 c6 f7 90 0f 0b 90 42 80 3c 2b 00
RSP: 0018:ffffc90000007900 EFLAGS: 00010246
RAX: ffffffff89f9ec80 RBX: ffff888033053780 RCX: ffff8880277c9e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007a10 R08: 0000000000000000 R09: ffffffff89d71b5d
R10: dffffc0000000000 R11: ffffffff89f9e0d0 R12: 0000000000000010
R13: dffffc0000000000 R14: ffff888075dfb100 R15: 0000000000000000
FS:  000055557e793380(0000) GS:ffff888125c52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe8999b9270 CR3: 00000000291c0000 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 cb 4e 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> d3 3a 28 f6 65 8b 05 bc 43 34 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000445f640 EFLAGS: 00000206
RAX: 718848643f7ff500 RBX: 0000000000000a02 RCX: 718848643f7ff500
RDX: 0000000000000006 RSI: ffffffff8d982ba6 RDI: 0000000000000001
RBP: ffffc9000445f6c0 R08: ffffffff8fa10ff7 R09: 1ffffffff1f421fe
R10: dffffc0000000000 R11: fffffbfff1f421ff R12: dffffc0000000000
R13: ffffffff8f574a40 R14: ffffffff8f574a00 R15: 1ffff9200088bec8
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:108
 netlink_unlock_table net/netlink/af_netlink.c:462 [inline]
 netlink_broadcast_filtered+0x108a/0x1140 net/netlink/af_netlink.c:1526
 nlmsg_multicast_filtered include/net/netlink.h:1151 [inline]
 nlmsg_multicast include/net/netlink.h:1170 [inline]
 nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2577
 vif_add+0x93f/0x1420 net/ipv4/ipmr.c:894
 ip_mroute_setsockopt+0xe12/0xf60 net/ipv4/ipmr.c:1455
 do_ip_setsockopt+0xf11/0x2d00 net/ipv4/ip_sockglue.c:948
 ip_setsockopt+0x66/0x110 net/ipv4/ip_sockglue.c:1417
 do_sock_setsockopt+0x25a/0x3e0 net/socket.c:2342
 __sys_setsockopt net/socket.c:2367 [inline]
 __do_sys_setsockopt net/socket.c:2373 [inline]
 __se_sys_setsockopt net/socket.c:2370 [inline]
 __x64_sys_setsockopt+0x18b/0x220 net/socket.c:2370
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe8999384c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcd7ef3cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000016417 RCX: 00007fe8999384c9
RDX: 00000000000000ca RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000010 R09: 0000000000000000
R10: 0000200000003d80 R11: 0000000000000246 R12: 00007ffcd7ef3cec
R13: 00007ffcd7ef3d20 R14: 00007ffcd7ef3d00 R15: 0000000000000001
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 05                	je     0x7
   2:	e8 cb 4e 5f f6       	call   0xf65f4ed2
   7:	48 c7 44 24 20 00 00 	movq   $0x0,0x20(%rsp)
   e:	00 00
  10:	9c                   	pushf
  11:	8f 44 24 20          	pop    0x20(%rsp)
  15:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  1a:	75 4f                	jne    0x6b
  1c:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 d3 3a 28 f6       	call   0xf6283b02 <-- trapping instruction
  2f:	65 8b 05 bc 43 34 07 	mov    %gs:0x73443bc(%rip),%eax        # 0x73443f2
  36:	85 c0                	test   %eax,%eax
  38:	74 40                	je     0x7a
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss