------------[ cut here ]------------
WARNING: net/ipv4/ipmr.c:2302 at ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302, CPU#1: syz.8.2092/12959
Modules linked in:
CPU: 1 UID: 0 PID: 12959 Comm: syz.8.2092 Not tainted 6.16.0-rc3-next-20250627-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 1e 18 be f7 48 8b 74 24 18 45 31 f6 31 ff ba 02 00 00 00 e8 0a fe 4b ff e9 45 f6 ff ff e8 00 18 be f7 90 <0f> 0b 90 e9 94 f5 ff ff e8 f2 17 be f7 90 0f 0b 90 42 80 3c 2b 00
RSP: 0018:ffffc90000a08900 EFLAGS: 00010246
RAX: ffffffff8a01ba60 RBX: ffff888064003640 RCX: ffff888028f40000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a08a10 R08: ffff888028f40000 R09: 0000000000000004
R10: 0000000000000003 R11: ffffffff8a01aeb0 R12: 0000000000000010
R13: dffffc0000000000 R14: ffff8880759bc400 R15: 0000000000000000
FS:  0000555589f60500(0000) GS:ffff888125d1e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000003c0 CR3: 000000002996c000 CR4: 00000000003526f0
DR0: 0000000000000007 DR1: 0000000000000002 DR2: 0000000000000008
DR3: 1000000100000000 DR6: 00000000ffff0ff0 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+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:arch_local_irq_restore arch/x86/include/asm/irqflags.h:158 [inline]
RIP: 0010:___slab_alloc+0x4a2/0x1410 mm/slub.c:3782
Code: 24 08 00 02 00 00 0f 84 c3 fb ff ff fb 89 dd e9 bb fb ff ff e8 ef ae 55 09 f7 c3 00 02 00 00 0f 84 96 fe ff ff fb 8b 6c 24 20 <eb> 19 48 8b 74 24 20 48 c7 46 10 00 00 00 00 4c 8b 2c 24 4c 89 ef
RSP: 0018:ffffc90004e9f510 EFLAGS: 00000206
RAX: c7fedc65738be200 RBX: 0000000000000246 RCX: c7fedc65738be200
RDX: 0000000000000006 RSI: ffffffff8d992a42 RDI: ffffffff8be31f80
RBP: 00000000ffffffff R08: ffffffff8fa18937 R09: 1ffffffff1f43126
R10: dffffc0000000000 R11: fffffbfff1f43127 R12: 0000000000000001
R13: ffff88801a491000 R14: ffff8880b873f5f0 R15: ffff8880b873f610
 __slab_alloc mm/slub.c:3981 [inline]
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4236
 mt_alloc_one lib/maple_tree.c:176 [inline]
 mas_alloc_nodes+0x2e9/0x8e0 lib/maple_tree.c:1249
 mas_node_count_gfp lib/maple_tree.c:1331 [inline]
 mas_preallocate+0x3ad/0x6f0 lib/maple_tree.c:5531
 vma_iter_prealloc mm/vma.h:463 [inline]
 __mmap_new_vma mm/vma.c:2472 [inline]
 __mmap_region mm/vma.c:2671 [inline]
 mmap_region+0xf1e/0x20c0 mm/vma.c:2741
 do_mmap+0xc45/0x10d0 mm/mmap.c:561
 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579
 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: 0033:0x7f436398e963
Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7
RSP: 002b:00007ffdfbedee68 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f4361ff76c0 RCX: 00007f436398e963
RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffdfbedefc0
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	24 08                	and    $0x8,%al
   2:	00 02                	add    %al,(%rdx)
   4:	00 00                	add    %al,(%rax)
   6:	0f 84 c3 fb ff ff    	je     0xfffffbcf
   c:	fb                   	sti
   d:	89 dd                	mov    %ebx,%ebp
   f:	e9 bb fb ff ff       	jmp    0xfffffbcf
  14:	e8 ef ae 55 09       	call   0x955af08
  19:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  1f:	0f 84 96 fe ff ff    	je     0xfffffebb
  25:	fb                   	sti
  26:	8b 6c 24 20          	mov    0x20(%rsp),%ebp
* 2a:	eb 19                	jmp    0x45 <-- trapping instruction
  2c:	48 8b 74 24 20       	mov    0x20(%rsp),%rsi
  31:	48 c7 46 10 00 00 00 	movq   $0x0,0x10(%rsi)
  38:	00
  39:	4c 8b 2c 24          	mov    (%rsp),%r13
  3d:	4c 89 ef             	mov    %r13,%rdi