rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11480/1:b..l P11331/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=44865, q=2534 ncpus=2)
task:syz.5.1272 state:R running task stack:25192 pid:11331 tgid:11322 ppid:5829 task_flags:0x40054c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_acquire+0xc4/0x340 kernel/locking/lockdep.c:5864
Code: 0f 85 eb 00 00 00 65 48 8b 04 25 08 b0 7e 92 83 b8 2c 0b 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 <4c> 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 52 71 7a 8d e8
RSP: 0018:ffffc90004c7f278 EFLAGS: 00000246
RAX: ffff888033f5db80 RBX: 0000000000000000 RCX: 97585e876f263700
RDX: 0000000000000000 RSI: ffffffff81743fa2 RDI: 1ffffffff1be8344
RBP: ffffffff81743f85 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff81ada120 R12: 0000000000000002
R13: ffffffff8df41a20 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2501 [inline]
slab_free mm/slub.c:6668 [inline]
kmem_cache_free+0x475/0x620 mm/slub.c:6779
exit_mmap+0x52c/0xb10 mm/mmap.c:1302
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 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+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa7abb915dc
RSP: 002b:00007fa7ac96be20 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 0000000000000024 RBX: 00007fa7ac96bfa0 RCX: 00007fa7abb915dc
RDX: 0000000000000024 RSI: 00007fa7ac96bff0 RDI: 0000000000000006
RBP: 0000000000000000 R08: 00007fa7ac96be74 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000006
R13: 0000000000000000 R14: 00007fa7ac96bff0 R15: 0000000000000000
task:syz.1.1309 state:R running task stack:22192 pid:11480 tgid:11480 ppid:10508 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:get_mem_cgroup_from_mm+0xaf/0x2a0 mm/memcontrol.c:938
Code: c7 40 cc 78 8b be 65 03 00 00 48 c7 c2 80 cc 78 8b e8 c5 a5 6e ff 49 81 c6 70 0a 00 00 4c 89 f5 48 c1 ed 03 42 80 7c 2d 00 00 <74> 08 4c 89 f7 e8 d7 f0 f7 ff 4d 8b 3e e8 cf aa 2b 09 85 c0 74 09
RSP: 0018:ffffc9000429e6c8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffff82301d08 RCX: 9cdfef87d5533600
RDX: 0000000001bebf44 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: 1ffff1100fed0f16 R08: ffffffff82301d08 R09: ffffffff8df41a20
R10: dffffc0000000000 R11: fffff9400020c959 R12: ffffea0001064ac8
R13: dffffc0000000000 R14: ffff88807f6878b0 R15: 0000000000000000
__mem_cgroup_charge+0x15/0x80 mm/memcontrol.c:4744
mem_cgroup_charge include/linux/memcontrol.h:663 [inline]
shmem_alloc_and_add_folio+0x790/0xf40 mm/shmem.c:1942
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2556
shmem_get_folio mm/shmem.c:2662 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3315
generic_perform_write+0x2c5/0x900 mm/filemap.c:4314
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3490
__kernel_write_iter+0x428/0x910 fs/read_write.c:619
dump_emit_page fs/coredump.c:1298 [inline]
dump_user_range+0x8a0/0xc90 fs/coredump.c:1372
elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111
coredump_write+0x1121/0x18b0 fs/coredump.c:1049
do_coredump fs/coredump.c:1126 [inline]
vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200
get_signal+0x1108/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x177/0x660 kernel/entry/common.c:196
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fc0f398f751
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fc0f3be6090 RCX: 00007fc0f398f749
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fc0f3a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fc0f3be6128 R14: 00007fc0f3be6090 R15: 00007ffd588bc7f8
rcu: rcu_preempt kthread starved for 10515 jiffies! g44865 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:27520 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 5e 83 b4 f5 cc cc cc 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 93 90 0c 00 f3 0f 1e fa fb f4 33 83 b4 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: 446d70aefecbb600 RBX: ffffffff81978fda RCX: 446d70aefecbb600
RDX: 0000000000000001 RSI: ffffffff8d7925c0 RDI: ffffffff8bc08360
RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f822070
R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f05f52a1c61 CR3: 0000000029a1d000 CR4: 0000000000350ef0
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+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3a7/0x400 init/main.c:1206
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147