rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5999/1:b..l
(detected by 0, t=10502 jiffies, g=17697, q=94)
task:syz.3.465 state:R running task stack:23472 pid: 5999 ppid: 4187 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0xc8/0x400 kernel/locking/lockdep.c:5594
rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
get_mem_cgroup_from_mm+0x31/0x260 mm/memcontrol.c:986
__mem_cgroup_charge+0x11/0x80 mm/memcontrol.c:6800
mem_cgroup_charge include/linux/memcontrol.h:700 [inline]
shmem_add_to_page_cache+0xa8a/0x14d0 mm/shmem.c:718
shmem_getpage_gfp+0x1735/0x2c10 mm/shmem.c:1940
shmem_getpage mm/shmem.c:151 [inline]
shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2474
generic_perform_write+0x2b6/0x550 mm/filemap.c:3785
__generic_file_write_iter+0x261/0x4e0 mm/filemap.c:3912
generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
__kernel_write+0x522/0x980 fs/read_write.c:539
__dump_emit+0x258/0x380 fs/coredump.c:943
dump_user_range+0x84/0x340 fs/coredump.c:1017
elf_core_dump+0x2fe0/0x3530 fs/binfmt_elf.c:2285
do_coredump+0x14e8/0x2a40 fs/coredump.c:894
get_signal+0x531/0x12e0 kernel/signal.c:2895
arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f2cdfb460e1
RSP: 002b:0000000000000030 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f2cdfdcdfa0 RCX: 00007f2cdfb460d9
RDX: 0000000000000000 RSI: 0000000000000030 RDI: 0000000000000600
RBP: 00007f2cdfbdd024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f2cdfdce038 R14: 00007f2cdfdcdfa0 R15: 00007fff531c8298
rcu: rcu_preempt kthread starved for 10422 jiffies! g17697 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27440 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 6086 Comm: syz.0.489 Tainted: G S syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x845/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x80 kernel/kcov.c:301
Code: 28 4d 39 ca 77 22 89 ff 89 f6 4a c7 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 <48> 8b 04 24 65 48 8b 0d 24 6f 89 7e 65 8b 15 25 6f 89 7e 81 e2 00
RSP: 0018:ffffc9000387fa98 EFLAGS: 00000246
RAX: 0000000000000475 RBX: ffffc9000387fc80 RCX: 0000000000080000
RDX: ffffc9000e83b000 RSI: 0000000000000475 RDI: 0000000000000001
RBP: ffffc9000387fbf0 R08: ffffffff8d8b0def R09: 1ffffffff1b161bd
R10: dffffc0000000000 R11: fffffbfff1b161be R12: dffffc0000000000
R13: 000000007ffff000 R14: 0000000000000475 R15: ffffffff8a38c288
splice_direct_to_actor+0x42f/0xc00 fs/splice.c:882
do_splice_direct+0x1d4/0x2f0 fs/splice.c:1008
do_sendfile+0x524/0xe30 fs/read_write.c:1249
__do_sys_sendfile64 fs/read_write.c:1317 [inline]
__se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1303
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc81fe440d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc81e07b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fc8200cc090 RCX: 00007fc81fe440d9
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00007fc81fedb024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000020000023896 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8200cc128 R14: 00007fc8200cc090 R15: 00007ffce8545cb8
vkms_vblank_simulate: vblank timer overrun