netlink: 4 bytes leftover after parsing attributes in process `syz.5.1527'. Oops: general protection fault, probably for non-canonical address 0xdffffc001fffe1ac: 0000 [#1] SMP KASAN NOPTI KASAN: probably user-memory-access in range [0x00000000ffff0d60-0x00000000ffff0d67] CPU: 0 UID: 0 PID: 11487 Comm: syz.5.1527 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:ip_mc_hash_remove net/ipv4/igmp.c:1431 [inline] RIP: 0010:__ip_mc_dec_group+0x25a/0x5b0 net/ipv4/igmp.c:1774 Code: ec 8d 23 f8 69 43 08 47 86 c8 61 49 bd 00 00 00 00 00 fc ff df c1 e8 17 4d 8d 24 c4 eb 2d e8 0d d6 bc f7 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 0f 85 1e 03 00 00 4d 8b 34 24 4c 39 f3 0f 84 ef 00 RSP: 0018:ffffc9000447eef0 EFLAGS: 00010206 RAX: 000000001fffe1ac RBX: ffff88802674d400 RCX: ffffc9001cea6000 RDX: 0000000000080000 RSI: ffffffff89ff4043 RDI: 0000000000000001 RBP: ffff8880570d6020 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 00000000ffff0d60 R13: dffffc0000000000 R14: 0000000000000001 R15: 00000000010000e0 FS: 00007f2f7e3f66c0(0000) GS:ffff88812475a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f7e3f5f98 CR3: 000000002f4a6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: inetdev_event+0x3b2/0x18a0 net/ipv4/devinet.c:1642 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1785 unregister_netdevice_many_notify+0x578/0x2700 net/core/dev.c:12047 rtnl_delete_link net/core/rtnetlink.c:3511 [inline] rtnl_dellink+0x3cb/0xa80 net/core/rtnetlink.c:3553 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmsg+0x16d/0x220 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2f8058e929 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:00007f2f7e3f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2f807b6080 RCX: 00007f2f8058e929 RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007f2f80610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2f807b6080 R15: 00007ffc26415ad8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:ip_mc_hash_remove net/ipv4/igmp.c:1431 [inline] RIP: 0010:__ip_mc_dec_group+0x25a/0x5b0 net/ipv4/igmp.c:1774 Code: ec 8d 23 f8 69 43 08 47 86 c8 61 49 bd 00 00 00 00 00 fc ff df c1 e8 17 4d 8d 24 c4 eb 2d e8 0d d6 bc f7 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 0f 85 1e 03 00 00 4d 8b 34 24 4c 39 f3 0f 84 ef 00 RSP: 0018:ffffc9000447eef0 EFLAGS: 00010206 RAX: 000000001fffe1ac RBX: ffff88802674d400 RCX: ffffc9001cea6000 RDX: 0000000000080000 RSI: ffffffff89ff4043 RDI: 0000000000000001 RBP: ffff8880570d6020 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 00000000ffff0d60 R13: dffffc0000000000 R14: 0000000000000001 R15: 00000000010000e0 FS: 00007f2f7e3f66c0(0000) GS:ffff88812475a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f7e3f5f98 CR3: 000000002f4a6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: ec in (%dx),%al 1: 8d 23 lea (%rbx),%esp 3: f8 clc 4: 69 43 08 47 86 c8 61 imul $0x61c88647,0x8(%rbx),%eax b: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 12: fc ff df 15: c1 e8 17 shr $0x17,%eax 18: 4d 8d 24 c4 lea (%r12,%rax,8),%r12 1c: eb 2d jmp 0x4b 1e: e8 0d d6 bc f7 call 0xf7bcd630 23: 4c 89 e0 mov %r12,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction 2f: 0f 85 1e 03 00 00 jne 0x353 35: 4d 8b 34 24 mov (%r12),%r14 39: 4c 39 f3 cmp %r14,%rbx 3c: 0f .byte 0xf 3d: 84 ef test %ch,%bh