rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11718/1:b..l P11888/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=74533, q=812 ncpus=2)
task:syz.1.1119 state:R running task stack:24664 pid:11888 tgid:11888 ppid:5847 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5354 [inline]
__schedule+0x165c/0x5520 kernel/sched/core.c:6966
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7151
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
zap_pte_range mm/memory.c:1948 [inline]
zap_pmd_range mm/memory.c:2004 [inline]
zap_pud_range mm/memory.c:2032 [inline]
zap_p4d_range mm/memory.c:2053 [inline]
__zap_vma_range+0x3d17/0x4b40 mm/memory.c:2093
unmap_vmas+0x379/0x530 mm/memory.c:2162
exit_mmap+0x280/0x9e0 mm/mmap.c:1300
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x18e/0x250 kernel/exit.c:581
do_exit+0x6a2/0x22c0 kernel/exit.c:963
do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
__do_sys_exit_group kernel/exit.c:1128 [inline]
__se_sys_exit_group kernel/exit.c:1126 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1126
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbad539c819
RSP: 002b:00007ffcff463368 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbad539c819
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcff4633cc R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000006 R11: 0000000000000246 R12: 00000000000000f3
R13: 00000000000927c0 R14: 000000000007aebb R15: 00007ffcff463420
task:syz.4.1086 state:R running task stack:20952 pid:11718 tgid:11718 ppid:5841 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5354 [inline]
__schedule+0x165c/0x5520 kernel/sched/core.c:6966
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7294
irqentry_exit+0x5e4/0x700 kernel/entry/common.c:240
asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 61 22 0d 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 1b 1e 9a 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 80 0e 10 0a cc 48 8d 3d 98 e8 92
RSP: 0018:ffffc90005185ef8 EFLAGS: 00000282
RAX: dcad981927882000 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000438b5f4e RSI: ffffffff8e2358fb RDI: ffffffff8c287de0
RBP: ffffffff81771256 R08: ffffffff81771256 R09: ffffffff8e95d260
R10: ffffc90005186058 R11: ffffffff81b15a30 R12: 0000000000000002
R13: ffffffff8e95d260 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
prep_new_page mm/page_alloc.c:1866 [inline]
get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2509
shmem_alloc_folio mm/shmem.c:1933 [inline]
shmem_alloc_and_add_folio+0x442/0xf80 mm/shmem.c:1975
shmem_get_folio_gfp+0x4d4/0x1420 mm/shmem.c:2552
shmem_get_folio mm/shmem.c:2658 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3291
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4325
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3466
__kernel_write_iter+0x41e/0x880 fs/read_write.c:621
dump_emit_page fs/coredump.c:1304 [inline]
dump_user_range+0xc19/0x12c0 fs/coredump.c:1378
elf_core_dump+0x34c2/0x3ad0 fs/binfmt_elf.c:2109
coredump_write+0x1216/0x1910 fs/coredump.c:1053
do_coredump fs/coredump.c:1132 [inline]
vfs_coredump+0x3807/0x4530 fs/coredump.c:1206
get_signal+0x1107/0x1330 kernel/signal.c:3022
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:283 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:352 [inline]
irqentry_exit+0x188/0x700 kernel/entry/common.c:219
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f13a339c821
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f13a3615fa0 RCX: 00007f13a339c819
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007f13a3432c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f13a3616038 R14: 00007f13a3615fa0 R15: 00007ffc59540708
rcu: rcu_preempt kthread starved for 10473 jiffies! g74533 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5354 [inline]
__schedule+0x165c/0x5520 kernel/sched/core.c:6966
__schedule_loop kernel/sched/core.c:7049 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7064
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
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 03/18/2026
RIP: 0010:sigismember include/linux/signal.h:87 [inline]
RIP: 0010:sig_ignored kernel/signal.c:113 [inline]
RIP: 0010:prepare_signal+0x24d/0xc10 kernel/signal.c:935
Code: fc 09 0f 94 c3 40 20 eb e9 2c 07 00 00 e8 db 3f 3b 00 4d 8d b5 90 09 00 00 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 85 a8 a4 00 49 63 dc 44 89 e5 4d 8b
RSP: 0018:ffffc90000a08c88 EFLAGS: 00000802
RAX: 1ffff110059d7132 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000010000 RSI: 0000000000000020 RDI: 000000000000001f
RBP: ffff88807952cac0 R08: ffffffff818a905a R09: ffff8880288e40d8
R10: 0000000000000000 R11: fffff52000141184 R12: 0000000000000020
R13: ffff88802ceb8000 R14: ffff88802ceb8990 R15: ffff88802ceb8980
FS: 0000000000000000(0000) GS:ffff88812535c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb148785980 CR3: 000000008407c000 CR4: 00000000003526f0
Call Trace:
posixtimer_send_sigqueue+0x337/0xa70 kernel/signal.c:2004
posix_timer_queue_signal kernel/time/posix-timers.c:357 [inline]
posix_timer_fn+0x11d/0x1b0 kernel/time/posix-timers.c:372
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x435/0x8e0 kernel/time/hrtimer.c:2112
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:steal_cookie_task kernel/sched/core.c:6368 [inline]
RIP: 0010:sched_core_balance+0x59e/0xde0 kernel/sched/core.c:6389
Code: c7 48 e8 f5 5a 1b 0a e9 75 05 00 00 48 8b 5c 24 10 48 8b 7c 24 28 48 83 c7 48 e8 dd 5a 1b 0a e8 c8 a4 37 00 fb 80 7c 24 1c 00 <4c> 8b b4 24 a0 00 00 00 4c 8b a4 24 98 00 00 00 48 8b 54 24 20 0f
RSP: 0018:ffffc90000197aa0 EFLAGS: 00000246
RAX: 0000000000ac191b RBX: ffff88801de80000 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8dfc0ce0 RDI: ffffffff8c287de0
RBP: dffffc0000000000 R08: ffffffff9031b4f7 R09: 1ffffffff206369e
R10: dffffc0000000000 R11: fffffbfff206369f R12: 1ffff110170e7794
R13: 0000000000000000 R14: 1ffff110170c7794 R15: 0000000000000001
do_balance_callbacks kernel/sched/core.c:4984 [inline]
__balance_callbacks kernel/sched/core.c:5040 [inline]
finish_lock_switch kernel/sched/core.c:5089 [inline]
finish_task_switch+0x5dd/0xbe0 kernel/sched/core.c:5209
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1664/0x5520 kernel/sched/core.c:6966
schedule_idle+0x51/0x90 kernel/sched/core.c:7090
do_idle+0x58a/0x5f0 kernel/sched/idle.c:381
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147