------------[ cut here ]------------
WARNING: net/ipv4/ipmr.c:2302 at ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302, CPU#1: syz.1.216/6897
Modules linked in:
CPU: 1 UID: 0 PID: 6897 Comm: syz.1.216 Not tainted 6.16.0-rc3-next-20250623-syzkaller #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 7e a7 be f7 48 8b 74 24 18 45 31 f6 31 ff ba 02 00 00 00 e8 fa 09 4c ff e9 45 f6 ff ff e8 60 a7 be f7 90 <0f> 0b 90 e9 94 f5 ff ff e8 52 a7 be f7 90 0f 0b 90 42 80 3c 2b 00
RSP: 0018:ffffc90000a08900 EFLAGS: 00010246
RAX: ffffffff8a012580 RBX: ffff888030d07780 RCX: ffff88802eb91e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a08a10 R08: ffff88802eb91e00 R09: 0000000000000004
R10: 0000000000000003 R11: ffffffff8a0119d0 R12: 0000000000000010
R13: dffffc0000000000 R14: ffff888079afd200 R15: 0000000000000000
FS:  00007fa86746b6c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000331030 CR3: 00000000710ae000 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+0x17b/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+0x283/0x870 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 7b 5a 57 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> f3 47 20 f6 65 8b 05 0c ab 2f 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90003e4f5e0 EFLAGS: 00000206
RAX: 6b754c05bd47fd00 RBX: 0000000000000a02 RCX: 6b754c05bd47fd00
RDX: 0000000000000006 RSI: ffffffff8d991910 RDI: 0000000000000001
RBP: ffffc90003e4f670 R08: ffffffff8fa18cf7 R09: 1ffffffff1f4319e
R10: dffffc0000000000 R11: fffffbfff1f4319f R12: dffffc0000000000
R13: ffff888021f9a840 R14: ffff888021f9a800 R15: 1ffff920007c9ebc
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:109
 __unix_dgram_recvmsg+0x49f/0xde0 net/unix/af_unix.c:2525
 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1063
 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2830
 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2874
 do_recvmmsg+0x307/0x770 net/socket.c:2969
 __sys_recvmmsg net/socket.c:3043 [inline]
 __do_sys_recvmmsg net/socket.c:3066 [inline]
 __se_sys_recvmmsg net/socket.c:3059 [inline]
 __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3059
 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: 0033:0x7fa86658e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa86746b038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fa8667b6080 RCX: 00007fa86658e929
RDX: 03fffffffffffcb5 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fa866610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fa8667b6080 R15: 00007ffccb5eb328
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 05                	je     0x7
   2:	e8 7b 5a 57 f6       	call   0xf6575a82
   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 f3 47 20 f6       	call   0xf6204822 <-- trapping instruction
  2f:	65 8b 05 0c ab 2f 07 	mov    %gs:0x72fab0c(%rip),%eax        # 0x72fab42
  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