rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P28490/1:b..l
	(detected by 1, t=10502 jiffies, g=261589, q=636)
task:syz-executor.3  state:R  running task     stack:27184 pid:28490 ppid: 15729 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xc8d/0x1270 kernel/sched/core.c:6287
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6687
 irqentry_exit+0x56/0x90 kernel/entry/common.c:425
 asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x8d/0x2f0 mm/kasan/generic.c:189
Code: ce 49 83 fe 10 7f 30 4d 85 f6 0f 84 ae 01 00 00 4c 89 cb 4c 29 d3 0f 1f 80 00 00 00 00 45 0f b6 19 45 84 db 0f 85 f3 01 00 00 <49> ff c1 48 ff c3 75 eb e9 87 01 00 00 44 89 cb 83 e3 07 0f 84 04
RSP: 0018:ffffc9000b48f748 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff8163fe6b
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ddbfae8
RBP: ffffc9000b48f910 R08: dffffc0000000000 R09: fffffbfff1bb7f5d
R10: fffffbfff1bb7f5e R11: 0000000000000000 R12: 1ffffffff1bb7f5d
R13: dffffc0000000001 R14: 0000000000000001 R15: dffffc0000000000
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 cpumask_test_cpu include/linux/cpumask.h:344 [inline]
 cpu_online include/linux/cpumask.h:895 [inline]
 trace_lock_acquire+0x3b/0x190 include/trace/events/lock.h:13
 lock_acquire+0xa5/0x4d0 kernel/locking/lockdep.c:5596
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267
 rcu_read_lock include/linux/rcupdate.h:687 [inline]
 ext4_get_group_desc+0x116/0x440 fs/ext4/balloc.c:284
 recently_deleted fs/ext4/ialloc.c:685 [inline]
 find_inode_bit+0x1f5/0x560 fs/ext4/ialloc.c:731
 __ext4_new_inode+0x102d/0x5650 fs/ext4/ialloc.c:1066
 ext4_symlink+0x4e1/0xfa0 fs/ext4/namei.c:3293
 vfs_symlink+0x379/0x590 fs/namei.c:4250
 do_symlinkat+0x22c/0x650 fs/namei.c:4279
 __do_sys_symlink fs/namei.c:4301 [inline]
 __se_sys_symlink fs/namei.c:4299 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4299
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f31b2b751e7
RSP: 002b:00007ffda7c1bfc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f31b2b751e7
RDX: 00007ffda7c1c0a3 RSI: 00007f31b2bcfd6b RDI: 00007ffda7c1c090
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffda7c1be60
R10: 00007ffda7c1bd17 R11: 0000000000000202 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffda7c1c090
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	49 83 fe 10          	cmp    $0x10,%r14
   4:	7f 30                	jg     0x36
   6:	4d 85 f6             	test   %r14,%r14
   9:	0f 84 ae 01 00 00    	je     0x1bd
   f:	4c 89 cb             	mov    %r9,%rbx
  12:	4c 29 d3             	sub    %r10,%rbx
  15:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  1c:	45 0f b6 19          	movzbl (%r9),%r11d
  20:	45 84 db             	test   %r11b,%r11b
  23:	0f 85 f3 01 00 00    	jne    0x21c
* 29:	49 ff c1             	inc    %r9 <-- trapping instruction
  2c:	48 ff c3             	inc    %rbx
  2f:	75 eb                	jne    0x1c
  31:	e9 87 01 00 00       	jmpq   0x1bd
  36:	44 89 cb             	mov    %r9d,%ebx
  39:	83 e3 07             	and    $0x7,%ebx
  3c:	0f                   	.byte 0xf
  3d:	84                   	.byte 0x84
  3e:	04                   	.byte 0x4