rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5824/1:b..l P6874/2:b..l
rcu: (detected by 1, t=10502 jiffies, g=16193, q=331 ncpus=2)
task:syz.5.265 state:R running task stack:25336 pid:6874 tgid:6872 ppid:5828 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 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:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:747
Code: c7 c7 e0 69 f4 8d e8 6f e9 1f 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 65 ff 05 d0 13 d9 10 e8 0b af b2 09 89
RSP: 0018:ffffc9000b92f7f8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff82303ac5 RCX: ffff888030c2db80
RDX: 00000000124408dd RSI: ffffffff8d975e7a RDI: ffffffff8bc083e0
RBP: 1ffff11006380f16 R08: ffffffff82303ac5 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: fffff9400023baf1 R12: ffff88801b29a80c
R13: dffffc0000000000 R14: ffff88801b29a7d0 R15: ffff88801b29a7c0
rcu_read_lock include/linux/rcupdate.h:868 [inline]
percpu_ref_tryget_many include/linux/percpu-refcount.h:241 [inline]
percpu_ref_tryget+0x43/0x180 include/linux/percpu-refcount.h:266
css_tryget include/linux/cgroup_refcnt.h:45 [inline]
get_mem_cgroup_from_mm+0x102/0x2a0 mm/memcontrol.c:941
__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
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb82818e1ff
RSP: 002b:00007fb828ff3df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fb82818e1ff
RDX: 0000000001000000 RSI: 00007fb81de00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000050f6
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fb828ff3ef0 R14: 00007fb828ff3eb0 R15: 00007fb81de00000
task:syz-executor state:R running task stack:21592 pid:5824 tgid:5824 ppid:5817 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 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:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217
Code: 08 10 80 92 65 8b 15 98 1a bf 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 6c 16 00 00 00 74 2c 8b 91 48 16 00 00 <83> fa 02 75 21 48 8b 91 50 16 00 00 48 8b 32 48 8d 7e 01 8b 89 4c
RSP: 0018:ffffc90002f875e0 EFLAGS: 00000246
RAX: ffffffff81f98af9 RBX: 0000000000001882 RCX: ffff8880798e8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffffd4000361281 R08: ffffea0001b09407 R09: 1ffffd4000361280
R10: dffffc0000000000 R11: fffff94000361281 R12: 0000000000001882
R13: 1ffffd4000361280 R14: ffffea0001b09400 R15: 0000000000000000
folio_nr_pages include/linux/mm.h:2259 [inline]
folio_contains+0x1d9/0x2b0 include/linux/pagemap.h:987
find_lock_entries+0x7a8/0xa60 mm/filemap.c:2184
shmem_undo_range+0x254/0x1490 mm/shmem.c:1119
shmem_truncate_range mm/shmem.c:1249 [inline]
shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379
evict+0x5f4/0xae0 fs/inode.c:837
do_unlinkat+0x340/0x560 fs/namei.c:5443
__do_sys_unlink fs/namei.c:5474 [inline]
__se_sys_unlink fs/namei.c:5472 [inline]
__x64_sys_unlink+0x47/0x50 fs/namei.c:5472
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9b7e58ecf7
RSP: 002b:00007ffc49e4d9c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9b7e58ecf7
RDX: 00007ffc49e4d9f0 RSI: 00007ffc49e4da80 RDI: 00007ffc49e4da80
RBP: 00007ffc49e4da80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc49e4eb10
R13: 00007f9b7e613d7d R14: 000000000002b3f4 R15: 00007ffc49e4eb50
rcu: rcu_preempt kthread starved for 10569 jiffies! g16193 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:27952 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 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+0x510/0xa50 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: 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 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 3e b4 b6 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 73 c1 0e 00 f3 0f 1e fa fb f4 13 b4 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2
RAX: 000000000025c5cd RBX: ffffffff819713be RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d791fea RDI: ffffffff8bc083e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822270
R13: 1ffff110038d6b70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000100 CR3: 000000005dccf000 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+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147