rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 ticks this GP) idle=8ce4/1/0x4000000000000000 softirq=53727/53727 fqs=2
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12081/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=42169, q=127 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10892 Comm: udevd Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:advance_sched+0x524/0xc90 net/sched/sch_taprio.c:961
Code: 48 89 44 24 50 48 c1 e8 03 48 89 44 24 70 48 89 6c 24 30 bf 10 00 00 00 4c 89 fe e8 66 36 3c f8 49 83 ff 0f 0f 87 f5 00 00 00 <4d> 8d b5 40 ff ff ff 4c 89 f5 48 c1 ed 03 42 80 7c 25 00 00 74 08
RSP: 0018:ffffc90000a08c70 EFLAGS: 00000093
RAX: ffffffff89840f1a RBX: 184bbdbbdaef6d72 RCX: ffff8880203e3c00
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000010
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200014117c R12: dffffc0000000000
R13: ffff88805708f4c8 R14: ffff88805708f400 R15: 0000000000000001
FS: 00007f8a00b6f880(0000) GS:ffff888125d59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dd1fffc CR3: 0000000078abc000 CR4: 00000000003526f0
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg+0x96/0x230 arch/x86/kernel/unwind_orc.c:403
Code: 89 f7 e8 ed f9 b0 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 4c 89 74 24 08 4d 8b 77 10 4c 89 fd 48 c1 ed 03 0f b6 44 35 00 <84> c0 0f 85 3c 01 00 00 41 83 3f 00 0f 95 c0 4c 39 c3 0f 96 c1 20
RSP: 0018:ffffc9000416f0a0 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffffc90004168000 RCX: 0000000000000000
RDX: ffffc9000416f268 RSI: dffffc0000000000 RDI: ffffc9000416f228
RBP: 1ffff9200082de45 R08: ffffc9000416f2b0 R09: 0000000000000000
R10: ffffc9000416f278 R11: fffff5200082de51 R12: 1ffff9200082de46
R13: 1ffff9200082de47 R14: ffffc90004170000 R15: ffffc9000416f228
unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763
folios_put_refs+0x559/0x640 mm/swap.c:992
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1125
shmem_truncate_range mm/shmem.c:1237 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365
evict+0x501/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:475
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8a004a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc3a7187a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f8a00b6f880 RCX: 00007f8a004a7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f8a00b6f6e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 000055be32bc23e0 R14: 0000000000000008 R15: 000055be32bd50d0
task:syz.5.1622 state:R running task stack:26792 pid:12081 tgid:12080 ppid:6775 task_flags:0x400040 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__rcu_read_unlock+0x63/0xe0 kernel/rcu/tree_plugin.h:443
Code: 75 1d 4c 8d b7 48 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 66 41 83 3e 00 75 27 43 0f b6 04 3c 84 c0 75 41 8b 03 <3d> 00 00 00 40 73 0f 5b 41 5c 41 5d 41 5e 41 5f e9 88 20 bf 09 cc
RSP: 0018:ffffc9000b8777d0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff88807f562244 RCX: c45e9c759f045600
RDX: 0000000000000003 RSI: ffffffff8db6a54c RDI: ffff88807f561e00
RBP: 1ffff1100db6da01 R08: 0000000000000000 R09: ffffffff822c40c5
R10: dffffc0000000000 R11: fffff940003b62f1 R12: 1ffff1100feac448
R13: dffffc0000000000 R14: ffff888028842710 R15: dffffc0000000000
rcu_read_unlock include/linux/rcupdate.h:873 [inline]
percpu_ref_tryget_many include/linux/percpu-refcount.h:250 [inline]
percpu_ref_tryget+0xfd/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:944
__mem_cgroup_charge+0x15/0x80 mm/memcontrol.c:4788
mem_cgroup_charge include/linux/memcontrol.h:652 [inline]
shmem_alloc_and_add_folio+0x7c1/0xf60 mm/shmem.c:1900
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2532
shmem_get_folio mm/shmem.c:2638 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3288
generic_perform_write+0x2c4/0x910 mm/filemap.c:4103
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3463
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x548/0xa90 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: 0033:0x7efc72b8d41f
RSP: 002b:00007efc73922df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007efc72b8d41f
RDX: 0000000001000000 RSI: 00007efc68400000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000004427
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007efc73922ef0 R14: 00007efc73922eb0 R15: 00007efc68400000
rcu: rcu_preempt kthread starved for 10495 jiffies! g42169 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x711/0x8a0 kernel/kthread.c:464
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:
CPU: 0 UID: 0 PID: 12091 Comm: syz.8.1626 Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xe69/0x11c0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 70 75 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 1b 71 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 00 71 0b
RSP: 0018:ffffc900045bf6e0 EFLAGS: 00000293
RAX: ffffffff81b4cfa0 RBX: ffff8880b863cb00 RCX: ffff88802f6d3c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900045bf840 R08: ffffc900045bf667 R09: 1ffff920008b7ecc
R10: dffffc0000000000 R11: fffff520008b7ecd R12: 1ffff110170e8285
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8741428
FS: 0000000000000000(0000) GS:ffff888125c59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555578c64808 CR3: 000000005c96e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:496
exit_mmap+0x44c/0xb50 mm/mmap.c:1297
__mmput+0x118/0x420 kernel/fork.c:1121
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x640/0x22e0 kernel/exit.c:943
do_group_exit+0x21c/0x2d0 kernel/exit.c:1104
__do_sys_exit_group kernel/exit.c:1115 [inline]
__se_sys_exit_group kernel/exit.c:1113 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7f86f258e969
Code: Unable to access opcode bytes at 0x7f86f258e93f.
RSP: 002b:00007fffd4869488 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f86f258e969
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffd48694ec R08: 00000003d486957f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000044
R13: 00000000000927c0 R14: 00000000000bfa22 R15: 00007fffd4869540