rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16835/1:b..l P5954/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=100949, q=126 ncpus=2)
task:udevd state:R running task stack:23328 pid:5954 tgid:5954 ppid:5192 task_flags:0x400140 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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:228 [inline]
RIP: 0010:unwind_next_frame+0x214/0x23c0 arch/x86/kernel/unwind_orc.c:510
Code: ef 08 8b 15 6e 41 a4 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 cc 7f 52 91 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 25 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d
RSP: 0018:ffffc9000481f8d8 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000000
RDX: 00000000000ab13c RSI: ffffffff8c27ae60 RDI: ffffffff8c27ae20
RBP: dffffc0000000000 R08: ffffffff81767a45 R09: ffffffff8e7602e0
R10: ffffc9000481f9f8 R11: ffffffff81b0bb90 R12: ffffffff81aac92d
R13: ffffffff91552af0 R14: ffffc9000481f9a8 R15: 000000000000aac9
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3131 [inline]
call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
slab_free_hook mm/slub.c:2656 [inline]
slab_free mm/slub.c:6143 [inline]
kmem_cache_free+0x439/0x630 mm/slub.c:6273
fput_close_sync+0x11f/0x240 fs/file_table.c:574
__do_sys_close fs/open.c:1509 [inline]
__se_sys_close fs/open.c:1494 [inline]
__x64_sys_close+0x7e/0x110 fs/open.c:1494
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: 0033:0x7f3f70915a67
RSP: 002b:00007fff1bb1f558 EFLAGS: 00000297 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000556163f70ae0 RCX: 00007f3f70915a67
RDX: 00007f3f709efea0 RSI: 0000556163f813a0 RDI: 0000000000000008
RBP: 00007f3f709efff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000
R13: 00007fff1bb1f9b0 R14: 0000000000000000 R15: 0000556163f59f80
task:syz.0.2667 state:R running task stack:24552 pid:16835 tgid:16829 ppid:5832 task_flags:0x40054c flags:0x08080000
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+0xa4/0x2e0 kernel/locking/lockdep.c:5844
Code: 3d 70 3c 70 0e 00 0f 84 c1 00 00 00 65 8b 05 53 82 7a 11 85 c0 0f 85 b2 00 00 00 65 48 8b 05 9b 3c 7a 11 83 b8 54 0b 00 00 00 <0f> 85 9d 00 00 00 9c 5b fa 48 c7 c7 dc c5 f0 8d e8 37 0a 0c 0a 65
RSP: 0000:ffffc9001bee6da8 EFLAGS: 00000246
RAX: ffff888035138000 RBX: 00000000ff000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff823c0867 RDI: 1ffffffff1cec05c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100dc882ac R12: 0000000000000002
R13: ffffffff8e7602e0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
__page_table_check_zero+0x87/0x3e0 mm/page_table_check.c:138
page_table_check_free include/linux/page_table_check.h:46 [inline]
__free_pages_prepare mm/page_alloc.c:1434 [inline]
free_unref_folios+0xeee/0x16d0 mm/page_alloc.c:3040
folios_put_refs+0x789/0x8d0 mm/swap.c:1002
free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:423
__tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:398 [inline]
tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405
zap_pte_range mm/memory.c:1968 [inline]
zap_pmd_range mm/memory.c:2021 [inline]
zap_pud_range mm/memory.c:2049 [inline]
zap_p4d_range mm/memory.c:2070 [inline]
unmap_page_range+0x3c1d/0x48f0 mm/memory.c:2091
unmap_single_vma mm/memory.c:2133 [inline]
unmap_vmas+0x48f/0x6a0 mm/memory.c:2171
exit_mmap+0x280/0xa10 mm/mmap.c:1302
__mmput+0x118/0x430 kernel/fork.c:1174
exit_mm+0x168/0x220 kernel/exit.c:581
do_exit+0x62e/0x2320 kernel/exit.c:959
do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
get_signal+0x1284/0x1330 kernel/signal.c:3034
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+0x86/0x480 kernel/entry/common.c:98
__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 include/linux/entry-common.h:325 [inline]
__do_fast_syscall_32+0x415/0x640 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f23f6c
RSP: 002b:00000000f53a45bc EFLAGS: 00000206 ORIG_RAX: 00000000000000f0
RAX: fffffffffffffe00 RBX: 00000000f73e50b8 RCX: 0000000000000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f73e50bc
RBP: 0000000000000081 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread timer wakeup didn't happen for 10493 jiffies! g100949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=45967
rcu: rcu_preempt kthread starved for 10494 jiffies! g100949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28120 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:467
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: 16800 Comm: syz.1.2657 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3850 [inline]
RIP: 0010:sched_mm_cid_fork+0x56c/0xc80 kernel/sched/core.c:10705
Code: 00 00 0f b6 c0 41 29 c6 4c 89 e3 e9 64 ff ff ff 49 c7 c5 98 be 1a 8e 49 c1 ed 03 eb 0b 44 89 e0 f7 d8 0f 81 2a fd ff ff f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 50 44 8b
RSP: 0000:ffffc9001c717c78 EFLAGS: 00000887
RAX: 0000000080000000 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff888055e5bc90
RBP: ffff888055e5bc90 R08: 1ffff1100abcb641 R09: 0000000000000000
R10: ffff888055e5b34c R11: fffff520038e2f80 R12: 0000000080000000
R13: 1ffffffff1c357d3 R14: 0000000000000002 R15: ffff888055e5b100
FS: 0000000000000000(0000) GS:ffff888125564000(0063) knlGS:00000000f5486b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080769000 CR3: 000000007cc0c000 CR4: 00000000003526f0
Call Trace:
bprm_execve+0xda1/0x1460 fs/exec.c:1771
do_execveat_common+0x50d/0x690 fs/exec.c:1846
__do_compat_sys_execveat fs/exec.c:1968 [inline]
__se_compat_sys_execveat fs/exec.c:1961 [inline]
__ia32_compat_sys_execveat+0xcd/0xf0 fs/exec.c:1961
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
do_int80_emulation+0x173/0x4d0 arch/x86/entry/syscall_32.c:172
asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0023:0xf7fc8f6c
Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 58 b8 77 00 00 00 cd 80 0f 0b 90 90 90 90 90 90 b8 ad
RSP: 002b:00000000f548650c EFLAGS: 00000206 ORIG_RAX: 0000000000000166
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000080000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000001000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000