syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6500/1:b..l
	(detected by 0, t=10502 jiffies, g=14053, q=285 ncpus=2)
task:kworker/u4:9    state:R  running task     stack:0     pid:6500  ppid:4722   flags:0x00000008
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 preempt_schedule_irq+0x8c/0x1b8 kernel/sched/core.c:6870
 arm64_preempt_schedule_irq arch/arm64/kernel/entry-common.c:265 [inline]
 __el1_irq arch/arm64/kernel/entry-common.c:474 [inline]
 el1_interrupt+0x4c/0x68 arch/arm64/kernel/entry-common.c:486
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
 seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline]
 read_seqbegin include/linux/seqlock.h:836 [inline]
 read_seqbegin_or_lock+0x160/0x250 include/linux/seqlock.h:1140
 prepend_path+0x1a8/0xb48 fs/d_path.c:165
 d_absolute_path+0x13c/0x27c fs/d_path.c:233
 d_namespace_path security/apparmor/path.c:125 [inline]
 aa_path_name+0x128/0xa98 security/apparmor/path.c:201
 profile_transition+0x198/0xe40 security/apparmor/domain.c:639
 apparmor_bprm_creds_for_exec+0x814/0x37ec security/apparmor/domain.c:898
 security_bprm_creds_for_exec+0x6c/0xa4 security/security.c:857
 bprm_execve+0x524/0x162c fs/exec.c:1843
 kernel_execve+0x718/0x7f0 fs/exec.c:2012
 call_usermodehelper_exec_async+0x21c/0x3c0 kernel/umh.c:113
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864
rcu: rcu_preempt kthread starved for 10500 jiffies! g14053 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:0     pid:16    ppid:2      flags:0x00000008
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2cc/0x1538 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xc0/0x308 kernel/rcu/tree.c:1905
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 1:
task:syz-executor.4  state:R  running task     stack:0     pid:6498  ppid:4248   flags:0x00000000
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 0xffff700003df6e38