rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8014/1:b..l P8001/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=23473, q=424 ncpus=2)
task:syz.3.502 state:R running task stack:25128 pid:8001 tgid:8000 ppid:5863 task_flags:0x40054c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1756 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0x3a79/0x4370 mm/memory.c:1889
unmap_single_vma mm/memory.c:1932 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1976
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__mmput+0x118/0x430 kernel/fork.c:1129
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f41a038ebe9
RSP: 002b:00007f41a12c4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000049
RAX: fffffffffffffe00 RBX: 00007f41a05b5fa0 RCX: 00007f41a038ebe9
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000007
RBP: 00007f41a0411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f41a05b6038 R14: 00007f41a05b5fa0 R15: 00007ffebf28df78
task:syz.4.508 state:R running task stack:25128 pid:8014 tgid:8013 ppid:5867 task_flags:0x400040 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:842 [inline]
RIP: 0010:blk_cgroup_congested+0x4d/0x210 block/blk-cgroup.c:2255
Code: 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 53 e8 e7 cd ec fc 48 83 c4 08 e8 fe 31 c8 06 89 c5 31 ff 89 c6 e8 03 23 0f fd <85> ed 74 10 e8 8a d0 f5 fc 84 c0 74 0e e8 b1 1e 0f fd eb 56 e8 aa
RSP: 0018:ffffc9001d4476d8 EFLAGS: 00000297
RAX: ffffffff84b08ced RBX: ffffffff84b08cbd RCX: 0000000000000002
RDX: ffff888025443c00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff84b08cbd
R10: dffffc0000000000 R11: fffff940002342b7 R12: ffffc9001d4477c0
R13: 0000000000000a92 R14: ffffea00011a1580 R15: dffffc0000000000
__folio_throttle_swaprate+0x80/0x1c0 mm/swapfile.c:3915
folio_throttle_swaprate include/linux/swap.h:653 [inline]
shmem_add_to_page_cache+0x6f1/0xba0 mm/shmem.c:919
shmem_alloc_and_add_folio+0x846/0xf60 mm/shmem.c:1973
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2597
shmem_get_folio mm/shmem.c:2703 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3353
generic_perform_write+0x2c5/0x900 mm/filemap.c:4175
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x54b/0xa90 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+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f228678d69f
RSP: 002b:00007f228760fdf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f228678d69f
RDX: 0000000001000000 RSI: 00007f227c400000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000061b0
R10: 0000000000000794 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f228760fef0 R14: 00007f228760feb0 R15: 00007f227c400000
rcu: rcu_preempt kthread starved for 10454 jiffies! g23473 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+0x3fc/0x770 arch/x86/kernel/process.c:148
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 6.16.0-syzkaller-12063-g37816488247d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 3e 8d 97 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 53 77 0f 00 f3 0f 1e fa fb f4 13 8d 97 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: 8e71deb9f44dee00 RBX: ffffffff81968308 RCX: 8e71deb9f44dee00
RDX: 0000000000000001 RSI: ffffffff8d9b4943 RDI: ffffffff8be32680
RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3
R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa34730
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d9b40
FS: 0000000000000000(0000) GS:ffff888125d21000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f76bcc5d3d8 CR3: 0000000023e3e000 CR4: 0000000000350ef0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147