BUG: MAX_LOCKDEP_CHAINS too low! turning off the locking correctness validator. CPU: 1 PID: 5379 Comm: kworker/u4:11 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 Workqueue: loop7 loop_workfn Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 add_chain_cache kernel/locking/lockdep.c:-1 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3772 [inline] validate_chain kernel/locking/lockdep.c:3793 [inline] __lock_acquire+0x1b40/0x6544 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662 _raw_spin_lock_nested+0x5c/0x78 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested kernel/sched/core.c:537 [inline] raw_spin_rq_lock kernel/sched/sched.h:1355 [inline] rq_lock kernel/sched/sched.h:1645 [inline] __schedule+0x2b8/0x1b18 kernel/sched/core.c:6477 preempt_schedule_notrace+0xc4/0x168 kernel/sched/core.c:6823 rcu_is_watching+0xf4/0x134 kernel/rcu/tree.c:722 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_held+0x18/0x50 kernel/rcu/update.c:309 xa_entry include/linux/xarray.h:1198 [inline] xas_descend+0x10c/0x41c lib/xarray.c:204 xas_load+0xa4/0x140 lib/xarray.c:242 mapping_get_entry mm/filemap.c:1881 [inline] __filemap_get_folio+0x184/0xab0 mm/filemap.c:1943 shmem_get_folio_gfp+0x240/0x2040 mm/shmem.c:1881 shmem_get_folio mm/shmem.c:2072 [inline] shmem_write_begin+0xf4/0x46c mm/shmem.c:2556 generic_perform_write+0x230/0x4b0 mm/filemap.c:3846 __generic_file_write_iter+0x168/0x37c mm/filemap.c:3974 generic_file_write_iter+0xb4/0x2b0 mm/filemap.c:4006 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x530/0x91c fs/read_write.c:861 vfs_iter_write+0x88/0xac fs/read_write.c:902 lo_write_bvec drivers/block/loop.c:244 [inline] lo_write_simple drivers/block/loop.c:266 [inline] do_req_filebacked drivers/block/loop.c:490 [inline] loop_handle_cmd drivers/block/loop.c:1907 [inline] loop_process_work+0xf54/0x1f8c drivers/block/loop.c:1942 loop_workfn+0x50/0x64 drivers/block/loop.c:1966 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850