netlink: 20 bytes leftover after parsing attributes in process `syz.4.353'. "mq-deadline" elevator initialization, failed -12, falling back to "none" ------------[ cut here ]------------ !rwb WARNING: block/blk-wbt.c:785 at wbt_init_enable_default+0x164/0x1c0 block/blk-wbt.c:785, CPU#0: syz.4.353/7354 Modules linked in: CPU: 0 UID: 0 PID: 7354 Comm: syz.4.353 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:wbt_init_enable_default+0x164/0x1c0 block/blk-wbt.c:785 Code: 1f 20 fd 5b 5d 41 5c 41 5d 41 5e e9 86 f5 aa 06 4c 89 f7 e8 ee ad 8c fd eb 83 4c 89 f7 e8 e4 ad 8c fd eb d0 e8 6d 1f 20 fd 90 <0f> 0b 90 e9 e9 fe ff ff e8 5f 1f 20 fd 90 0f 0b 90 48 b8 00 00 00 RSP: 0018:ffffc9000432f180 EFLAGS: 00010283 RAX: 000000000001cbf4 RBX: ffff88802b3c7000 RCX: ffffc9000f309000 RDX: 0000000000080000 RSI: ffffffff84e8d673 RDI: ffffffff8c1b12a0 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff827583ab R12: ffff88802be51310 R13: ffff8880332ca4ec R14: ffff88802b3c7390 R15: ffff88802be51320 FS: 00007fce8cb2b6c0(0000) GS:ffff88812433f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ff03ff8 CR3: 0000000037a67000 CR4: 00000000003526f0 Call Trace: blk_register_queue+0x42c/0x590 block/blk-sysfs.c:949 __add_disk+0x73f/0xe40 block/genhd.c:528 add_disk_fwnode+0x118/0x5c0 block/genhd.c:597 add_disk include/linux/blkdev.h:785 [inline] nbd_dev_add+0x77a/0xb10 drivers/block/nbd.c:1984 nbd_genl_connect+0xb8d/0x1a40 drivers/block/nbd.c:2125 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2592 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646 __sys_sendmsg+0x170/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fce8bb9c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fce8cb2b028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fce8be15fa0 RCX: 00007fce8bb9c799 RDX: 0000000000000004 RSI: 0000200000000240 RDI: 0000000000000004 RBP: 00007fce8bc32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fce8be16038 R14: 00007fce8be15fa0 R15: 00007fff676a1c38