[v5.15] INFO: rcu detected stall in sys_rt_sigreturn

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9465fef4ae35 Linux 5.15.153
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16fbbfb1180000
kernel config: https://syzkaller.appspot.com/x/.config?x=74ff83133fa97f6c
dashboard link: https://syzkaller.appspot.com/bug?extid=45c71f99506e933fd050
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=130e65b1180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12b143e5180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3c82fda40b43/disk-9465fef4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ec13893dc103/vmlinux-9465fef4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7b44910e5283/Image-9465fef4.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+45c71f...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 1, t=10502 jiffies, g=3225, q=15)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294954681-4294944179), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g3225 f0x2 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: 15 ppid: 2 flags:0x00000008
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1884
rcu_gp_fqs_loop+0x26c/0x13d4 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145
kthread+0x37c/0x45c kernel/kthread.c:319
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 1:
task:syz-executor313 state:R running task stack: 0 pid: 3991 ppid: 3966 flags:0x00000001
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
sched_show_task+0x43c/0x574 kernel/sched/core.c:8640
dump_cpu_task+0x84/0xa8 kernel/sched/core.c:10914
rcu_check_gp_kthread_starvation+0x1f0/0x254 kernel/rcu/tree_stall.h:488
print_other_cpu_stall+0x202c/0x2290 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3932 [inline]
rcu_sched_clock_irq+0x1894/0x1b8c kernel/rcu/tree.c:2619
update_process_times+0x1d4/0x270 kernel/time/timer.c:1788
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x340/0x4f8 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1686 [inline]
__hrtimer_run_queues+0x458/0xca4 kernel/time/hrtimer.c:1750
hrtimer_interrupt+0x2c0/0xb64 kernel/time/hrtimer.c:1812
timer_handler drivers/clocksource/arm_arch_timer.c:659 [inline]
arch_timer_handler_virt+0x74/0x88 drivers/clocksource/arm_arch_timer.c:670
handle_percpu_devid_irq+0x29c/0x7fc kernel/irq/chip.c:933
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq_desc kernel/irq/irqdesc.c:651 [inline]
handle_domain_irq+0xec/0x178 kernel/irq/irqdesc.c:706
gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:758
call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899
do_interrupt_handler+0x74/0x94 arch/arm64/kernel/entry-common.c:267
el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470
el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:580
__sanitizer_cov_trace_pc+0x88/0x94 kernel/kcov.c:205
check_preemption_disabled+0x38/0x164 lib/smp_processor_id.c:16
debug_smp_processor_id+0x20/0x2c lib/smp_processor_id.c:60
rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
rcu_is_watching+0x5c/0x18c kernel/rcu/tree.c:1123
trace_lock_release include/trace/events/lock.h:58 [inline]
lock_release+0xe4/0xa1c kernel/locking/lockdep.c:5634
__might_fault+0xf4/0x128 mm/memory.c:5324
__copy_from_user include/linux/uaccess.h:109 [inline]
restore_fpsimd_context arch/arm64/kernel/signal.c:204 [inline]
restore_sigframe arch/arm64/kernel/signal.c:528 [inline]
__arm64_sys_rt_sigreturn+0x16b8/0x22ec arch/arm64/kernel/signal.c:555
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584


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