rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6223/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=16101, q=838 ncpus=2)
task:syz.2.99 state:R running task stack:26552 pid:6223 tgid:6221 ppid:5625 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0x970 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: f6 7f 5c 00 48 89 df 5b e9 bd 10 62 00 be 03 00 00 00 5b e9 92 ab f0 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 c5 1f 01 12 48 8b 34 24 65 48 8b 15 a1 1f 01
RSP: 0000:ffffc90008b47928 EFLAGS: 00000202
RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffffffff82457c1b
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff888030184a80
RBP: ffffea00010a16c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffea00010a16f4
R13: ffffc90008b47958 R14: 0000000000000001 R15: 0000000000000d64
raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline]
raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline]
atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline]
page_ref_add_unless_zero include/linux/page_ref.h:233 [inline]
folio_ref_add_unless_zero include/linux/page_ref.h:242 [inline]
folio_try_get include/linux/page_ref.h:258 [inline]
filemap_get_entry+0x1b8/0x450 mm/filemap.c:1911
shmem_get_folio_gfp+0xa4c/0x1900 mm/shmem.c:2488
shmem_get_folio mm/shmem.c:2670 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3303
generic_perform_write+0x292/0xa40 mm/filemap.c:4325
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3478
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1070 fs/read_write.c:688
ksys_write+0x12a/0x250 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f646d19ce59
RSP: 002b:00007f646b3cd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f646d416090 RCX: 00007f646d19ce59
RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000008
RBP: 00007f646d232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f646d416128 R14: 00007f646d416090 R15: 00007ffd69b5c298
rcu: rcu_preempt kthread starved for 10525 jiffies! g16101 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:27992 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: b6 92 02 e9 43 44 03 00 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 e3 11 22 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000242
RAX: 00000000014e91df RBX: ffffffff8e4955c0 RCX: ffffffff8b898225
RDX: 0000000000000000 RSI: ffffffff8df0f8f1 RDI: ffffffff8c1c4680
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170867b5
R10: ffff8880b8433dab R11: 0000000000000000 R12: 0000000000000000
R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90d71150
FS: 0000000000000000(0000) GS:ffff888124383000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc878f86480 CR3: 000000007a9fe000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
rest_init+0x251/0x260 init/main.c:762
start_kernel+0x484/0x490 init/main.c:1220
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148