------------[ cut here ]------------
WARNING: CPU: 0 PID: 7397 at net/ipv4/ipmr.c:2302 ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302
Modules linked in:
CPU: 0 UID: 0 PID: 7397 Comm: syz.0.306 Not tainted 6.16.0-rc2-syzkaller-00622-g091d019adce0 #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 2e 16 c6 f7 48 8b 74 24 18 45 31 f6 31 ff ba 02 00 00 00 e8 7a 0b 4c ff e9 45 f6 ff ff e8 10 16 c6 f7 90 <0f> 0b 90 e9 94 f5 ff ff e8 02 16 c6 f7 90 0f 0b 90 42 80 3c 2b 00
RSP: 0018:ffffc90000007900 EFLAGS: 00010246
RAX: ffffffff89fa4640 RBX: ffff888030e8a140 RCX: ffff88802c44bc00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007a10 R08: ffff88802c44bc00 R09: 0000000000000004
R10: 0000000000000003 R11: ffffffff89fa3a90 R12: 0000000000000010
R13: dffffc0000000000 R14: ffff88805cebbf00 R15: 0000000000000000
FS:  00007f31ece276c0(0000) GS:ffff888125c4f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa089b6eff8 CR3: 000000006117a000 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:console_flush_all+0x7f7/0xc40 kernel/printk/printk.c:3227
Code: 48 21 c3 0f 85 e9 01 00 00 e8 15 24 1f 00 48 8b 5c 24 20 4d 85 f6 75 07 e8 06 24 1f 00 eb 06 e8 ff 23 1f 00 fb 48 8b 44 24 28 <42> 80 3c 20 00 74 08 48 89 df e8 0a a2 82 00 48 8b 1b 48 8b 44 24
RSP: 0018:ffffc9000486f240 EFLAGS: 00000287
RAX: 1ffffffff1d36aab RBX: ffffffff8e9b5558 RCX: 0000000000080000
RDX: ffffc9000c7e9000 RSI: 000000000000cbce RDI: 000000000000cbcf
RBP: ffffc9000486f390 R08: ffffffff8fa120f7 R09: 1ffffffff1f4241e
R10: dffffc0000000000 R11: fffffbfff1f4241f R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000200 R15: ffffffff8e9b5500
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 _printk+0xcf/0x120 kernel/printk/printk.c:2475
 netdev_info+0x10a/0x160 net/core/dev.c:12605
 netif_set_allmulti+0x1b8/0x380 net/core/dev.c:9376
 dev_set_allmulti+0x12b/0x260 net/core/dev_api.c:313
 ipmr_new_tunnel net/ipv4/ipmr.c:492 [inline]
 vif_add+0xdfd/0x1420 net/ipv4/ipmr.c:861
 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+0x257/0x3e0 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: 0033:0x7f31ebf8e929
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:00007f31ece27038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f31ec1b5fa0 RCX: 00007f31ebf8e929
RDX: 00000000000000ca RSI: 0000000000000000 RDI: 000000000000000c
RBP: 00007f31ec010b39 R08: 0000000000000010 R09: 0000000000000000
R10: 0000200000000140 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f31ec1b5fa0 R15: 00007ffdb70fd788
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 21 c3             	and    %rax,%rbx
   3:	0f 85 e9 01 00 00    	jne    0x1f2
   9:	e8 15 24 1f 00       	call   0x1f2423
   e:	48 8b 5c 24 20       	mov    0x20(%rsp),%rbx
  13:	4d 85 f6             	test   %r14,%r14
  16:	75 07                	jne    0x1f
  18:	e8 06 24 1f 00       	call   0x1f2423
  1d:	eb 06                	jmp    0x25
  1f:	e8 ff 23 1f 00       	call   0x1f2423
  24:	fb                   	sti
  25:	48 8b 44 24 28       	mov    0x28(%rsp),%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 0a a2 82 00       	call   0x82a243
  39:	48 8b 1b             	mov    (%rbx),%rbx
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	44                   	rex.R
  3f:	24                   	.byte 0x24