rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6634/1:b..l P6822/2:b..l
rcu: (detected by 0, t=10502 jiffies, g=15769, q=1449 ncpus=2)
task:syz.2.214 state:R running task stack:24960 pid:6822 tgid:6821 ppid:5821 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7235
irqentry_exit+0x599/0x620 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d7/0x3d0 kernel/locking/lockdep.c:5893
Code: 5b 7a 11 00 00 00 00 eb b5 e8 f5 27 0c 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 75 15 7a 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 45 86 6e ff cc 48 8d 3d 72 27 73
RSP: 0018:ffffc900034377b0 EFLAGS: 00000282
RAX: aa2bc24e2f633f00 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000003 RSI: ffffffff8e1655da RDI: ffffffff8c27b380
RBP: ffff8880271d6750 R08: ffffffff82397d95 R09: ffffffff8e75e3e0
R10: dffffc0000000000 R11: fffff940001d94f1 R12: 0000000000000003
R13: 0000000000000003 R14: ffffffff8e75e3e0 R15: ffff8880271d5b80
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
percpu_ref_tryget_many include/linux/percpu-refcount.h:250 [inline]
percpu_ref_tryget+0xf8/0x180 include/linux/percpu-refcount.h:266
css_tryget include/linux/cgroup_refcnt.h:45 [inline]
get_mem_cgroup_from_mm+0x102/0x290 mm/memcontrol.c:959
__mem_cgroup_charge+0x25/0x1e0 mm/memcontrol.c:4760
mem_cgroup_charge include/linux/memcontrol.h:664 [inline]
shmem_alloc_and_add_folio+0x7d0/0xf80 mm/shmem.c:1982
shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2567
shmem_get_folio mm/shmem.c:2673 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3327
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4319
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3502
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbfdc95cfce
RSP: 002b:00007fbfdd894da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbfdd8956c0 RCX: 00007fbfdc95cfce
RDX: 0000000000080000 RSI: 00007fbfd2600000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007fbfdd894ee0 R14: 00007fbfdd894ea0 R15: 00007fbfd2600000
task:syz.4.176 state:R running task stack:21408 pid:6634 tgid:6634 ppid:5819 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7235
irqentry_exit+0x599/0x620 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872
Code: e9 30 ff ff ff e8 35 59 0c 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 b1 46 7a 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 81 b7 6e ff cc 48 8d 3d 3e 55 73
RSP: 0018:ffffc90003185ef8 EFLAGS: 00000282
RAX: 627ff3a9c3ee2b00 RBX: 0000000000000246 RCX: 0000000000000046
RDX: 0000000088789759 RSI: ffffffff8e1655da RDI: ffffffff8c27b380
RBP: 0000000000000000 R08: ffffffff81767de5 R09: ffffffff8e75e3e0
R10: dffffc0000000000 R11: ffffffff81b0bfa0 R12: 0000000000000002
R13: ffffffff8e75e3e0 R14: 0000000000000000 R15: 0000000000000000
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+0xc2/0x23c0 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:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2484
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2503
shmem_alloc_folio mm/shmem.c:1930 [inline]
shmem_alloc_and_add_folio+0x445/0xf80 mm/shmem.c:1972
shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2567
shmem_get_folio mm/shmem.c:2673 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3327
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4319
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3502
__kernel_write_iter+0x41e/0x880 fs/read_write.c:621
dump_emit_page fs/coredump.c:1299 [inline]
dump_user_range+0xb89/0x12d0 fs/coredump.c:1373
elf_core_dump+0x34c2/0x3ad0 fs/binfmt_elf.c:2110
coredump_write+0x1216/0x1910 fs/coredump.c:1050
do_coredump fs/coredump.c:1127 [inline]
vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201
get_signal+0x1107/0x1330 kernel/signal.c:3019
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: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+0x176/0x620 kernel/entry/common.c:219
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f5cb6d9c7a1
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f5cb7016090 RCX: 00007f5cb6d9c799
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f5cb6e32bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f5cb7016128 R14: 00007f5cb7016090 R15: 00007ffd9f47a418
rcu: rcu_preempt kthread starved for 8942 jiffies! g15769 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:28296 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
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+0x51e/0xb90 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 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: fe 6c 02 e9 8e 62 62 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 43 82 1b 00 fb f4 67 62 62 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000242
RAX: 00000000006f07d3 RBX: ffffffff819a8c8d RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8def4b2d RDI: ffffffff8c27b380
RBP: ffffc90000197f10 R08: ffff8880b873395b R09: 1ffff110170e672b
R10: dffffc0000000000 R11: ffffed10170e672c R12: ffffffff90118bb0
R13: 1ffff11003ad7000 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125563000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbfdd874d58 CR3: 0000000021364000 CR4: 0000000000350ef0
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1bd/0x500 kernel/sched/idle.c:332
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147