------------[ cut here ]------------ WARNING: CPU: 0 PID: 10581 at net/ipv4/ipmr.c:2302 ip_mr_output+0xbb1/0xe70 net/ipv4/ipmr.c:2302 Modules linked in: CPU: 0 UID: 0 PID: 10581 Comm: syz-executor Not tainted 6.16.0-rc2-syzkaller-00625-g27390db9592d #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 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 70 16 c6 f7 90 <0f> 0b 90 e9 94 f5 ff ff e8 62 16 c6 f7 90 0f 0b 90 42 80 3c 2b 00 RSP: 0018:ffffc90000007900 EFLAGS: 00010246 RAX: ffffffff89fa45e0 RBX: ffff8880406953c0 RCX: ffff88802fa39e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007a10 R08: ffff88802fa39e00 R09: 0000000000000004 R10: 0000000000000003 R11: ffffffff89fa3a30 R12: 0000000000000010 R13: dffffc0000000000 R14: ffff8880682abb00 R15: 0000000000000000 FS: 0000555557138500(0000) GS:ffff888125c4f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c367e59 CR3: 000000006f1fc000 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+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 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:ffffc9000aece820 EFLAGS: 00000293 RAX: 1ffffffff1d36aab RBX: ffffffff8e9b5558 RCX: ffff88802fa39e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000aece970 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 br_set_state+0x475/0x710 net/bridge/br_stp.c:57 new_nbp+0x303/0x440 net/bridge/br_if.c:443 br_add_if+0x28e/0xec0 net/bridge/br_if.c:599 do_set_master+0x530/0x6d0 net/core/rtnetlink.c:2946 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3148 rtnl_changelink net/core/rtnetlink.c:3759 [inline] __rtnl_newlink net/core/rtnetlink.c:3918 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 __sys_sendto+0x3bd/0x520 net/socket.c:2226 __do_sys_sendto net/socket.c:2233 [inline] __se_sys_sendto net/socket.c:2229 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2229 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: 0033:0x7fb3323907bc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffead3cfdd0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fb3330e4620 RCX: 00007fb3323907bc RDX: 0000000000000028 RSI: 00007fb3330e4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffead3cfe24 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fb3330e4670 R15: 0000000000000000 ---------------- 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