rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=faf4/1/0x4000000000000000 softirq=181733/181738 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=191729, q=208 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 22478 Comm: syz.6.4418 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:mark_lock+0x9a/0x190 kernel/locking/lockdep.c:4774
Code: 0e 00 75 13 48 8d 3d 85 e4 72 0e 48 c7 c6 f9 88 00 8e 67 48 0f b9 3a 90 31 c9 4c 89 fe 4c 89 f7 b8 01 00 00 00 85 69 60 74 10 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49 89 fe 49 89 f7
RSP: 0018:ffffc90004f4fad0 EFLAGS: 00000006
RAX: 0000000000000001 RBX: 0000000000000008 RCX: ffffffff93c57410
RDX: 0000000000000008 RSI: ffff88802d022980 RDI: ffff88802d021e40
RBP: 0000000000000100 R08: ffffffff84fce68a R09: ffffffff8ef4ed98
R10: dffffc0000000000 R11: fffffbfff1de9db1 R12: 0000000000000003
R13: ffff88802d022980 R14: ffff88802d021e40 R15: 0000000000000001
FS: 000055555fc63500(0000) GS:ffff88812546f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4499456b8 CR3: 0000000087cae000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:4674 [inline]
__lock_acquire+0x6b5/0x2cf0 kernel/locking/lockdep.c:5191
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
vga_put drivers/pci/vgaarb.c:547 [inline]
vga_arb_release+0x1fa/0x5d0 drivers/pci/vgaarb.c:1425
__fput+0x44f/0xa70 fs/file_table.c:469
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/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_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f620c39bf79
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:00007f620c73fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f620c73fc90 RCX: 00007f620c39bf79
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00000000001649bd R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b33020000 R11: 0000000000000246 R12: 00007f620c73fcd0
R13: 00007f620c615fac R14: 00000000001649fc R15: 00007f620c615fa0
rcu: rcu_preempt kthread starved for 10502 jiffies! g191729 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:27944 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
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:
CPU: 1 UID: 0 PID: 20921 Comm: syz-executor 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:unwind_next_frame+0x138f/0x23c0 arch/x86/kernel/unwind_orc.c:656
Code: 14 24 4d 89 3c 24 41 0f b6 44 2d 00 84 c0 0f 85 02 0e 00 00 c6 03 00 4c 8b 64 24 48 4c 8b 7c 24 28 48 8b 44 24 40 0f b6 04 28 <84> c0 0f 85 6c 0b 00 00 41 0f b6 04 2f 84 c0 0f 85 83 0b 00 00 0f
RSP: 0018:ffffc90000a086b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90000a087c0 RCX: 0000000000000000
RDX: ffffffff90b1d47e RSI: 0000000000000000 RDI: ffffc90000a087e8
RBP: dffffc0000000000 R08: ffffc90000a087e7 R09: 0000000000000000
R10: ffffc90000a087d8 R11: fffff520001410fd R12: ffffc90000a087d8
R13: 1ffff920001410f3 R14: ffffc90000a08788 R15: 1ffffffff2163a8f
FS: 000055557b829500(0000) GS:ffff88812556f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f620c44e661 CR3: 0000000043af2000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2670 [inline]
slab_free mm/slub.c:6082 [inline]
kmem_cache_free+0x187/0x630 mm/slub.c:6212
skb_kfree_head net/core/skbuff.c:1087 [inline]
skb_free_head net/core/skbuff.c:1101 [inline]
skb_release_data+0x6c3/0x940 net/core/skbuff.c:1128
skb_release_all net/core/skbuff.c:1203 [inline]
__kfree_skb+0x5d/0x210 net/core/skbuff.c:1217
mac80211_hwsim_beacon_tx+0x3e8/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2365
__iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:760
ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:796
mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xce5/0x12c0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 a4 e2 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 4f de 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 33 de
RSP: 0018:ffffc90005a4f600 EFLAGS: 00000293
RAX: ffffffff81b9a9cd RBX: 1ffff110170c8515 RCX: ffff88802dba1e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005a4f728 R08: ffffffff90114db7 R09: 1ffffffff20229b6
R10: dffffc0000000000 R11: fffffbfff20229b7 R12: ffff8880b86428a8
R13: dffffc0000000000 R14: ffff8880b873bf80 R15: 0000000000000000
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x5c3/0x10c0 arch/x86/mm/tlb.c:1472
dup_mmap+0x15de/0x1b80 mm/mmap.c:1866
dup_mm kernel/fork.c:1530 [inline]
copy_mm+0x13b/0x4b0 kernel/fork.c:1582
copy_process+0x18b6/0x3cf0 kernel/fork.c:2223
kernel_clone+0x248/0x8e0 kernel/fork.c:2654
__do_sys_clone kernel/fork.c:2795 [inline]
__se_sys_clone kernel/fork.c:2779 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2779
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: 0033:0x7fe448bc4a12
Code: 89 e7 e8 f1 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007fe448f3fc60 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fe448f3fc60 RCX: 00007fe448bc4a12
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fe448f3fdec R08: 0000000000000000 R09: 0000000000000001
R10: 000055557b8297d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000164934 R15: 00007fe448f3fe40