rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=fa8c/1/0x4000000000000000 softirq=14933/14933 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6322/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=11937, q=660 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6302 Comm: syz.0.172 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3837 [inline]
RIP: 0010:sched_mm_cid_fork+0x576/0xc80 kernel/sched/core.c:10704
Code: e3 e9 64 ff ff ff 49 c7 c5 98 1e 2c 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 35 71 2d 96 0c 48 89 ef 4c 89
RSP: 0018:ffffc9000378fc78 EFLAGS: 00000887
RAX: dffffc0000000000 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff888033bbb050
RBP: ffff888033bbb050 R08: 1ffff110067774b9 R09: 0000000000000000
R10: ffff888033bba70c R11: fffff520006f1f80 R12: 0000000080000000
R13: 1ffffffff1c583d3 R14: 0000000000000002 R15: ffff888033bba4c0
FS: 00007facd3eda6c0(0000) GS:ffff888125015000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f171da73ff8 CR3: 0000000074d2e000 CR4: 00000000003526f0
Call Trace:
bprm_execve+0xda1/0x1460 fs/exec.c:1771
do_execveat_common+0x50d/0x690 fs/exec.c:1846
__do_sys_execveat fs/exec.c:1941 [inline]
__se_sys_execveat fs/exec.c:1934 [inline]
__x64_sys_execveat+0xc7/0xf0 fs/exec.c:1934
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: 0033:0x7facd2f9aeb9
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:00007facd3eda028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007facd3215fa0 RCX: 00007facd2f9aeb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007facd3008c1f R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007facd3216038 R14: 00007facd3215fa0 R15: 00007ffe8a559568
task:syz.1.176 state:R running task stack:26072 pid:6322 tgid:6312 ppid:5821 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5310 kernel/sched/core.c:6907
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234
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:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline]
RIP: 0010:lock_acquire+0x95/0x2e0 kernel/locking/lockdep.c:5844
Code: 00 48 8b 74 24 68 4c 89 ef e8 d7 cf 8d 00 83 3d 40 98 91 0e 00 0f 84 c1 00 00 00 65 8b 05 d3 18 9f 11 85 c0 0f 85 b2 00 00 00 <65> 48 8b 05 1b d3 9e 11 83 b8 14 0b 00 00 00 0f 85 9d 00 00 00 9c
RSP: 0018:ffffc900037373c0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000010002bd RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff823a28eb RDI: 1ffffffff1d2c064
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: ffffffff81b11240 R12: 0000000000000002
R13: ffffffff8e960320 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
__update_page_owner_free_handle+0x4b/0x470 mm/page_owner.c:283
__reset_page_owner+0x85/0x1f0 mm/page_owner.c:321
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1432 [inline]
__free_frozen_pages+0xc01/0xd80 mm/page_alloc.c:2972
__folio_put+0x414/0x4f0 mm/swap.c:112
folio_put include/linux/mm.h:1817 [inline]
migrate_folio_done mm/migrate.c:1199 [inline]
migrate_folio_move mm/migrate.c:1413 [inline]
migrate_folios_move mm/migrate.c:1721 [inline]
migrate_pages_batch+0x3593/0x4d80 mm/migrate.c:1977
migrate_pages_sync mm/migrate.c:2007 [inline]
migrate_pages+0x1c74/0x2a70 mm/migrate.c:2116
do_mbind mm/mempolicy.c:1609 [inline]
kernel_mbind mm/mempolicy.c:1752 [inline]
__do_sys_mbind mm/mempolicy.c:1826 [inline]
__se_sys_mbind+0xe89/0x10f0 mm/mempolicy.c:1822
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: 0033:0x7fdf8339aeb9
RSP: 002b:00007fdf815f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007fdf83616090 RCX: 00007fdf8339aeb9
RDX: 0000000000000001 RSI: 0000000000c00000 RDI: 0000200000400000
RBP: 00007fdf83408c1f R08: 0000000000000000 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdf83616128 R14: 00007fdf83616090 R15: 00007ffd3feef208
rcu: rcu_preempt kthread starved for 10502 jiffies! g11937 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:27664 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5310 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: 49 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events_unbound toggle_allocation_gate
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 34 e3 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 df 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 c3 de
RSP: 0018:ffffc90000b97760 EFLAGS: 00000293
RAX: ffffffff81ba0f0d RBX: 1ffff11017088515 RCX: ffff8880232f9e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b978a0 R08: ffffffff903342b7 R09: 1ffffffff2066856
R10: dffffc0000000000 R11: fffffbfff2066857 R12: ffff8880b84428a8
R13: dffffc0000000000 R14: ffff8880b853bf80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125115000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb3c49e4198 CR3: 000000000e74c000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2746 [inline]
smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2956
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
toggle_allocation_gate+0x1fe/0x290 mm/kfence/core.c:906
process_one_work+0x949/0x1650 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
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