BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! turning off the locking correctness validator. CPU: 0 UID: 0 PID: 6894 Comm: syz.0.998 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 add_chain_cache kernel/locking/lockdep.c:-1 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3899 [inline] validate_chain kernel/locking/lockdep.c:3920 [inline] __lock_acquire+0xed4/0x2b08 kernel/locking/lockdep.c:5288 lock_acquire+0x13c/0x320 kernel/locking/lockdep.c:5942 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_lock_irq+0x58/0x70 kernel/locking/spinlock.c:189 __wait_for_common kernel/sched/completion.c:120 [inline] wait_for_common+0xa0/0x394 kernel/sched/completion.c:132 wait_for_completion+0x18/0x24 kernel/sched/completion.c:153 __synchronize_srcu+0x1cc/0x268 kernel/rcu/srcutree.c:1477 synchronize_srcu+0x280/0x2e0 kernel/rcu/srcutree.c:-1 blk_mq_wait_quiesce_done+0x88/0xac block/blk-mq.c:284 blk_mq_quiesce_queue+0x70/0x8c block/blk-mq.c:304 elevator_switch+0x128/0x38c block/elevator.c:576 elevator_change+0x204/0x35c block/elevator.c:681 elevator_set_default+0x190/0x2b0 block/elevator.c:754 blk_register_queue+0x2fc/0x3d4 block/blk-sysfs.c:992 __add_disk+0x5c8/0xbdc block/genhd.c:531 add_disk_fwnode+0xd4/0x340 block/genhd.c:600 device_add_disk+0x38/0x4c block/genhd.c:630 add_disk include/linux/blkdev.h:798 [inline] nbd_dev_add+0x594/0x884 drivers/block/nbd.c:2026 nbd_genl_connect+0x7f4/0x12b0 drivers/block/nbd.c:2223 genl_family_rcv_msg_doit+0x1e4/0x2d4 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x43c/0x620 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x238/0x414 net/netlink/af_netlink.c:2575 genl_rcv+0x38/0x50 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline] netlink_unicast+0x600/0x7f8 net/netlink/af_netlink.c:1364 netlink_sendmsg+0x648/0x948 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg+0xc8/0x17c net/socket.c:815 ____sys_sendmsg+0x3d0/0x6c8 net/socket.c:2713 ___sys_sendmsg+0x198/0x224 net/socket.c:2767 __sys_sendmsg+0x158/0x204 net/socket.c:2799 __do_sys_sendmsg net/socket.c:2804 [inline] __se_sys_sendmsg net/socket.c:2802 [inline] __arm64_sys_sendmsg+0x88/0x9c net/socket.c:2802 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606