GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12269/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=68265, q=314 ncpus=2)
task:syz.7.1637 state:R running task stack:23376 pid:12269 tgid:12269 ppid:7665 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
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+0x205/0xa00 kernel/entry/common.c:167
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67
Code: e9 c2 fa ff ff 48 c7 c7 58 c2 cb 8b e8 f9 7e c2 00 e9 1e fa ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> 8b 07 e9 58 26 04 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90
RSP: 0018:ffffc900074be2c0 EFLAGS: 00000202
RAX: ffffc900074c0001 RBX: 0000000000000001 RCX: ffffffff91d40b3e
RDX: ffffc900074be501 RSI: ffffc900074be550 RDI: ffffc900074be550
RBP: ffffc900074be550 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 00000000000184d1 R12: ffffc900074be388
R13: ffffc900074be338 R14: ffffc900074be580 R15: ffffc900074be36c
deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline]
unwind_next_frame+0x1561/0x2090 arch/x86/kernel/unwind_orc.c:677
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__set_page_owner+0x8c/0x540 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1907
shmem_alloc_and_add_folio+0x371/0xd40 mm/shmem.c:1949
shmem_get_folio_gfp+0x6ad/0x1910 mm/shmem.c:2502
shmem_get_folio mm/shmem.c:2608 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3239
generic_perform_write+0x292/0xa40 mm/filemap.c:4358
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3414
__kernel_write_iter+0x2ac/0x930 fs/read_write.c:621
dump_emit_page fs/coredump.c:1298 [inline]
dump_user_range+0x3f9/0xad0 fs/coredump.c:1372
elf_core_dump+0x2d68/0x3d20 fs/binfmt_elf.c:2109
coredump_write fs/coredump.c:1052 [inline]
do_coredump fs/coredump.c:1131 [inline]
vfs_coredump+0x294b/0x56f0 fs/coredump.c:1200
get_signal+0x1f2a/0x21e0 kernel/signal.c:3023
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
irqentry_exit+0x402/0xa00 kernel/entry/common.c:165
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f360859de61
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f3608826090 RCX: 00007f360859de59
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f3608633e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f3608826128 R14: 00007f3608826090 R15: 00007ffd029b5808
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g68265 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=38084
rcu: rcu_preempt kthread starved for 10502 jiffies! g68265 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12315 Comm: syz.0.1649 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:qdisc_dev include/net/sch_generic.h:612 [inline]
RIP: 0010:advance_sched+0x7b/0xd20 net/sched/sch_taprio.c:922
Code: 40 48 89 44 24 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 a6 0b 00 00 48 8b 44 24 28 48 8b 68 40 <48> b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 0f
RSP: 0018:ffffc90000a08de8 EFLAGS: 00000046
RAX: ffff888055453000 RBX: ffff888055453300 RCX: ffff888055453280
RDX: 1ffff1100aa8a608 RSI: ffffffff89c6d31e RDI: ffff888055453040
RBP: ffff88807f03b800 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888055453300
R13: ffffffff89c6d300 R14: ffff8880b8528640 R15: ffff8880b8528690
FS: 00007f048d85f6c0(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33309ff8 CR3: 0000000062b08000 CR4: 00000000003526f0
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 3b df 7d 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 86 c5 3c 0f 0f 82 ac 02 00 00 8b 35 4e f9 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd de 7d 12 0f 85 ec 02 00 00 48 83 c4
RSP: 0018:ffffc90006d67c18 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 04baeae17f23ea81
RDX: 0000000000000000 RSI: ffffffff8e17cd3b RDI: ffffffff8c400c80
RBP: ffffffff8ea78230 R08: 00000000ffffffff R09: 0000000000000003
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
cpus_read_lock+0x42/0x170 kernel/cpu.c:490
class_cpus_read_lock_constructor include/linux/cpuhplock.h:49 [inline]
clock_was_set+0x96/0x850 kernel/time/hrtimer.c:988
do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1684
do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195
__do_sys_clock_settime kernel/time/posix-timers.c:1139 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1123 [inline]
__x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1123
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: 0033:0x7f048c99de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f048d85f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f048cc26090 RCX: 00007f048c99de59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f048ca33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f048cc26128 R14: 00007f048cc26090 R15: 00007ffc71c2a9b8