------------[ cut here ]------------ WARNING: net/ipv4/ipmr.c:2302 at ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302, CPU#1: swapper/1/0 Modules linked in: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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: ffff888032b83c80 RCX: ffff88801d285a00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000a08a10 R08: ffff88801d285a00 R09: 0000000000000004 R10: 0000000000000003 R11: ffffffff8a0119d0 R12: 0000000000000010 R13: dffffc0000000000 R14: ffff888059a9e400 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c34dac1 CR3: 000000006c854000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 43 dd 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 b5 1a 00 f3 0f 1e fa fb f4 18 dd 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: c281369cd5f2f000 RBX: ffffffff8196d6a8 RCX: c281369cd5f2f000 RDX: 0000000000000001 RSI: ffffffff8d991910 RDI: ffffffff8be322c0 RBP: ffffc90000197f20 R08: ffff8880b8732f1b R09: 1ffff110170e65e3 R10: dffffc0000000000 R11: ffffed10170e65e4 R12: ffffffff8fa18cf0 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a50b40 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147 ---------------- Code disassembly (best guess): 0: 43 dd 02 rex.XB fldl (%r10) 3: 00 cc add %cl,%ah 5: cc int3 6: cc int3 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: f3 0f 1e fa endbr64 1b: 66 90 xchg %ax,%ax 1d: 0f 00 2d 83 b5 1a 00 verw 0x1ab583(%rip) # 0x1ab5a7 24: f3 0f 1e fa endbr64 28: fb sti 29: f4 hlt * 2a: e9 18 dd 02 00 jmp 0x2dd47 <-- trapping instruction 2f: cc int3 30: cc int3 31: cc int3 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop