GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
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): P13715/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=74549, q=154 ncpus=2)
task:syz.2.2020 state:R running task stack:25480 pid:13715 ppid:5773 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6700
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
follow_page_pte+0xbd6/0x1ae0 mm/gup.c:594
__get_user_pages+0x58d/0x1580 mm/gup.c:1165
populate_vma_page_range+0x2c1/0x380 mm/gup.c:1593
__mm_populate+0x260/0x390 mm/gup.c:1696
mm_populate include/linux/mm.h:3383 [inline]
vm_mmap_pgoff+0x2da/0x3f0 mm/util.c:561
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6b6cd9de59
RSP: 002b:00007f6b6dbed028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f6b6d026090 RCX: 00007f6b6cd9de59
RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f6b6ce33e6f R08: ffffffffffffffff R09: 0000000000004000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6b6d026128 R14: 00007f6b6d026090 R15: 00007ffcc80d30c8
rcu: rcu_preempt kthread starved for 10245 jiffies! g74549 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:27848 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_region_inline mm/kasan/generic.c:-1 [inline]
RIP: 0010:kasan_check_range+0xf/0x290 mm/kasan/generic.c:187
Code: 31 c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b4 01 00 00 <55> 41 57 41 56 41 55 41 54 53 4c 8d 04 37 49 39 f8 0f 82 13 02 00
RSP: 0018:ffffc900001f07d8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81680367
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e8c6b28
RBP: ffffc900001f08e8 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d18d66 R12: 1ffff9200003e108
R13: ffffffff8d14b948 R14: 0000000000000001 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c90f194088 CR3: 000000004339f000 CR4: 00000000003506e0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
cpumask_test_cpu include/linux/cpumask.h:504 [inline]
cpu_online include/linux/cpumask.h:1082 [inline]
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0xb7/0x420 kernel/locking/lockdep.c:5725
seqcount_lockdep_reader_access+0xd1/0x1d0 include/linux/seqlock.h:102
timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
ktime_get+0x7f/0x280 kernel/time/timekeeping.c:848
clockevents_program_event+0xe6/0x310 kernel/time/clockevents.c:326
hrtimer_interrupt+0x565/0x980 kernel/time/hrtimer.c:1893
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc900001f0c20 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 1d527d0a279e9a00
RDX: 0000000000000000 RSI: ffffffff8acadce0 RDI: ffffffff8b1cfa20
RBP: ffffc900001f0d38 R08: dffffc0000000000 R09: 1ffffffff223ced6
R10: dffffc0000000000 R11: fffffbfff223ced7 R12: 1ffff9200003e190
R13: ffff8880538bc108 R14: 0000000000000246 R15: dffffc0000000000
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
net_tx_action+0x6e7/0x950 net/core/dev.c:5293
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 4c 1d 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 43 77 3c 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9
RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6
RAX: 1d527d0a279e9a00 RBX: ffffffff81628c14 RCX: 1d527d0a279e9a00
RDX: 0000000000000001 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20
RBP: ffffc90000187f20 R08: ffff8880b8f36bab R09: 1ffff110171e6d75
R10: dffffc0000000000 R11: ffffed10171e6d76 R12: 1ffff92000030fc8
R13: dffffc0000000000 R14: 1ffff1100384d780 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x334/0x5c0 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323
secondary_startup_64_no_verify+0x179/0x17b