rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9840/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=196493, q=572 ncpus=2)
task:syz.1.10785 state:R running task stack:24592 pid:9840 tgid:9830 ppid:4191 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:stack_access_ok+0x12/0x200 arch/x86/kernel/unwind_orc.c:405
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 4c 8d 77 08 <41> 55 41 54 49 89 d4 4c 89 f2 55 48 c1 ea 03 48 89 f5 53 48 89 fb
RSP: 0018:ffffc9000bbcf480 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff911ff806
RDX: 0000000000000008 RSI: ffffc9000bbcf5f0 RDI: ffffc9000bbcf558
RBP: ffffc9000bbcf5a0 R08: ffffffff911ff80a R09: 00000000d27c185d
R10: 0000000000000002 R11: 000000000000637a R12: ffffc9000bbcf5a8
R13: ffffc9000bbcf558 R14: ffffc9000bbcf560 R15: ffffc9000bbcf58c
deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
unwind_next_frame+0xb7d/0x20b0 arch/x86/kernel/unwind_orc.c:600
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
__call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3119
slab_free_hook mm/slub.c:2504 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x171/0x770 mm/slub.c:6781
exit_mmap+0x507/0xb60 mm/mmap.c:1302
__mmput+0x12a/0x410 kernel/fork.c:1173
mmput+0x62/0x70 kernel/fork.c:1196
exit_mm kernel/exit.c:581 [inline]
do_exit+0x7d7/0x2bd0 kernel/exit.c:959
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5eadf8f749
RSP: 002b:00007f5eac1d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f5eae1e6090 RCX: 00007f5eadf8f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f5eae013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5eae1e6128 R14: 00007f5eae1e6090 R15: 00007fff6e0d53a8
rcu: rcu_preempt kthread starved for 10542 jiffies! g196493 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:27936 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: c6 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 49 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 000000000a0d559b RBX: 0000000000000001 RCX: ffffffff8b7816d9
RDX: 0000000000000000 RSI: ffffffff8dace4f3 RDI: ffffffff8bf2b480
RBP: ffffed1003b56498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801dab2ff0 R12: 0000000000000001
R13: ffff88801dab24c0 R14: ffffffff9088b9d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30e20ff8 CR3: 0000000081abf000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148