netlink: 'syz.4.4995': attribute type 27 has an invalid length. gretap0: left promiscuous mode sit0: left promiscuous mode Oops: general protection fault, probably for non-canonical address 0xdffffc001fffe1ac: 0000 [#1] SMP KASAN PTI KASAN: probably user-memory-access in range [0x00000000ffff0d60-0x00000000ffff0d67] CPU: 0 UID: 0 PID: 24520 Comm: syz.4.4995 Not tainted 6.16.0-syzkaller-06588-g759dfc7d04ba #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:ip_mc_hash_remove net/ipv4/igmp.c:1431 [inline] RIP: 0010:__ip_mc_dec_group+0x2fd/0x690 net/ipv4/igmp.c:1774 Code: 99 e8 c4 f7 c6 05 23 96 8f 05 01 48 c7 c7 a0 f7 9b 8c be 97 05 00 00 48 c7 c2 20 f8 9b 8c e8 ea d2 a2 f7 4c 89 e3 48 c1 eb 03 <42> 80 3c 2b 00 74 08 4c 89 e7 e8 54 0b 28 f8 4d 8b 2c 24 4d 39 f5 RSP: 0018:ffffc9000b0c68f8 EFLAGS: 00010206 RAX: ffffffff89fac7de RBX: 000000001fffe1ac RCX: 0000000000080000 RDX: ffffc9001c451000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffff888031d00020 R08: ffffffff8f508fa7 R09: 1ffffffff1ea11f4 R10: dffffc0000000000 R11: fffffbfff1ea11f5 R12: 00000000ffff0d60 R13: dffffc0000000000 R14: ffff8881404b8e00 R15: 1ffff110063a0004 FS: 00007f2b9de6a6c0(0000) GS:ffff888125c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f26d4df5f98 CR3: 000000007f8d4000 CR4: 00000000003526f0 Call Trace: inetdev_event+0x2a7/0x15b0 net/ipv4/devinet.c:1642 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9608 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3143 rtnl_group_changelink net/core/rtnetlink.c:3775 [inline] __rtnl_newlink net/core/rtnetlink.c:3929 [inline] rtnl_newlink+0x149f/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 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: 0033:0x7f2b9cf8eb69 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:00007f2b9de6a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2b9d1b5fa0 RCX: 00007f2b9cf8eb69 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f2b9d011df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2b9d1b5fa0 R15: 00007ffcac350898 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:ip_mc_hash_remove net/ipv4/igmp.c:1431 [inline] RIP: 0010:__ip_mc_dec_group+0x2fd/0x690 net/ipv4/igmp.c:1774 Code: 99 e8 c4 f7 c6 05 23 96 8f 05 01 48 c7 c7 a0 f7 9b 8c be 97 05 00 00 48 c7 c2 20 f8 9b 8c e8 ea d2 a2 f7 4c 89 e3 48 c1 eb 03 <42> 80 3c 2b 00 74 08 4c 89 e7 e8 54 0b 28 f8 4d 8b 2c 24 4d 39 f5 RSP: 0018:ffffc9000b0c68f8 EFLAGS: 00010206 RAX: ffffffff89fac7de RBX: 000000001fffe1ac RCX: 0000000000080000 RDX: ffffc9001c451000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffff888031d00020 R08: ffffffff8f508fa7 R09: 1ffffffff1ea11f4 R10: dffffc0000000000 R11: fffffbfff1ea11f5 R12: 00000000ffff0d60 R13: dffffc0000000000 R14: ffff8881404b8e00 R15: 1ffff110063a0004 FS: 00007f2b9de6a6c0(0000) GS:ffff888125d80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007f8d4000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 99 cltd 1: e8 c4 f7 c6 05 call 0x5c6f7ca 6: 23 96 8f 05 01 48 and 0x4801058f(%rsi),%edx c: c7 c7 a0 f7 9b 8c mov $0x8c9bf7a0,%edi 12: be 97 05 00 00 mov $0x597,%esi 17: 48 c7 c2 20 f8 9b 8c mov $0xffffffff8c9bf820,%rdx 1e: e8 ea d2 a2 f7 call 0xf7a2d30d 23: 4c 89 e3 mov %r12,%rbx 26: 48 c1 eb 03 shr $0x3,%rbx * 2a: 42 80 3c 2b 00 cmpb $0x0,(%rbx,%r13,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 4c 89 e7 mov %r12,%rdi 34: e8 54 0b 28 f8 call 0xf8280b8d 39: 4d 8b 2c 24 mov (%r12),%r13 3d: 4d 39 f5 cmp %r14,%r13