syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6545/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=10609, q=110973 ncpus=2)
task:udevd           state:R  running task     stack:0     pid:6545  tgid:6545  ppid:6145   task_flags:0x400140 flags:0x00000008
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x141c/0x2a14 kernel/sched/core.c:6786
 preempt_schedule_irq+0x80/0x188 kernel/sched/core.c:7109
 arm64_preempt_schedule_irq+0x44/0x58 arch/arm64/kernel/entry-common.c:305
 __el1_irq arch/arm64/kernel/entry-common.c:656 [inline]
 el1_interrupt+0x3c/0x54 arch/arm64/kernel/entry-common.c:668
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:673
 el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592
 check_region_inline mm/kasan/generic.c:177 [inline] (P)
 kasan_check_range+0x3c/0x2a4 mm/kasan/generic.c:189 (P)
 __kasan_check_read+0x20/0x30 mm/kasan/shadow.c:31
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
 __page_table_check_zero+0x224/0x414 mm/page_table_check.c:143
 page_table_check_free include/linux/page_table_check.h:43 [inline]
 free_pages_prepare mm/page_alloc.c:1249 [inline]
 __free_frozen_pages+0xc10/0xd2c mm/page_alloc.c:2706
 free_frozen_pages+0x14/0x20 mm/page_alloc.c:2744
 __free_slab+0x110/0x1e8 mm/slub.c:2688
 free_slab+0x24/0x120 mm/slub.c:2711
 discard_slab mm/slub.c:2717 [inline]
 __put_partials+0x19c/0x244 mm/slub.c:3186
 put_cpu_partial+0x164/0x1c0 mm/slub.c:3261
 __slab_free+0x1b0/0x280 mm/slub.c:4513
 do_slab_free mm/slub.c:4595 [inline]
 ___cache_free+0x150/0x170 mm/slub.c:4701
 qlink_free+0x48/0x94 mm/kasan/quarantine.c:163
 qlist_free_all+0x44/0xb8 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x118/0x124 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x2c/0x88 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x238/0x3e8 mm/slub.c:4204
 locks_alloc_lock fs/locks.c:275 [inline]
 flock_lock_inode+0x1b4/0x11f4 fs/locks.c:1091
 flock_lock_inode_wait fs/locks.c:2084 [inline]
 locks_lock_inode_wait+0xf0/0x3c8 fs/locks.c:2111
 locks_lock_file_wait include/linux/filelock.h:422 [inline]
 __do_sys_flock fs/locks.c:2179 [inline]
 __se_sys_flock fs/locks.c:2135 [inline]
 __arm64_sys_flock+0x3e0/0x5f0 fs/locks.c:2135
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596