rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=3e54/1/0x4000000000000000 softirq=227129/227130 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P24714/1:b..l P25516/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=207701, q=200 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 25492 Comm: syz.7.4481 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3759 [inline]
RIP: 0010:sched_mm_cid_fork+0x2f7/0xc30 kernel/sched/core.c:10578
Code: 01 00 00 85 ed 0f 84 0b 01 00 00 31 ed 31 db e9 c1 01 00 00 49 c7 c5 c8 f4 9a 8d 49 c1 ed 03 eb 07 44 89 e0 f7 d8 71 8d f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 50 44 8b
RSP: 0018:ffffc90012ed7c78 EFLAGS: 00000887
RAX: 0000000080000000 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff888024410b90
RBP: ffff888024410b90 R08: 1ffff11004882021 R09: 0000000000000000
R10: ffff888024410254 R11: ffff888024410110 R12: 0000000080000000
R13: 1ffffffff1b35e99 R14: 0000000000000002 R15: ffff888024410000
FS: 00007f3861f5a6c0(0000) GS:ffff888125e21000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000266030 CR3: 0000000046332000 CR4: 00000000003526f0
Call Trace:
bprm_execve+0xd88/0x1400 fs/exec.c:1776
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execveat fs/exec.c:1944 [inline]
__do_sys_execveat fs/exec.c:2018 [inline]
__se_sys_execveat fs/exec.c:2012 [inline]
__x64_sys_execveat+0xc4/0xe0 fs/exec.c:2012
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f386118f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3861f5a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f38613e5fa0 RCX: 00007f386118f749
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007f3861213f91 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f38613e6038 R14: 00007f38613e5fa0 R15: 00007f386150fa28
task:syz.3.4485 state:R running task stack:26176 pid:25516 tgid:25515 ppid:20744 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 00 a1 bb 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0a 00 e2 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 37 76 e7
RSP: 0018:ffffc90014d47520 EFLAGS: 00000282
RAX: f18ef1e88ab11200 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000b5c0162b RSI: ffffffff8d975e82 RDI: ffffffff8bc083e0
RBP: ffffffff81f9766d R08: ffffffff81f9766d R09: ffffffff8df41aa0
R10: ffffc90014d475a0 R11: fffff520029a8eb7 R12: 0000000000000002
R13: ffffffff8df41aa0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
filemap_get_entry+0xc9/0x2f0 mm/filemap.c:1892
shmem_get_folio_gfp+0x237/0x1660 mm/shmem.c:2480
shmem_fault+0x179/0x390 mm/shmem.c:2757
__do_fault+0x138/0x390 mm/memory.c:5320
do_read_fault mm/memory.c:5755 [inline]
do_fault mm/memory.c:5889 [inline]
do_pte_missing+0x2206/0x3330 mm/memory.c:4401
handle_pte_fault mm/memory.c:6273 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x1650/0x29f0 mm/gup.c:1428
populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860
__mm_populate+0x24c/0x380 mm/gup.c:1963
mm_populate include/linux/mm.h:3701 [inline]
vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f865f78f749
RSP: 002b:00007f866068e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f865f9e5fa0 RCX: 00007f865f78f749
RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f865f813f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f865f9e6038 R14: 00007f865f9e5fa0 R15: 00007f865fb0fa28
task:udevd state:R running task stack:24568 pid:24714 tgid:24714 ppid:5199 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x188/0x23d0 arch/x86/kernel/unwind_orc.c:-1
Code: 8d 5e 35 48 89 d8 48 c1 e8 03 48 89 44 24 28 0f b6 04 28 84 c0 0f 85 4c 1b 00 00 4c 89 6c 24 48 4c 89 64 24 20 4c 89 7c 24 50 <48> 89 5c 24 18 0f b6 1b 48 8b 44 24 30 80 3c 28 00 4c 8b 7c 24 10
RSP: 0018:ffffc9000ce3f478 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc9000ce3f57d RCX: 0000000080000001
RDX: 000000005a44979c RSI: ffffffff8bc083c0 RDI: ffffffff8bc08380
RBP: dffffc0000000000 R08: ffffffff8173fd65 R09: ffffffff8df41aa0
R10: ffffc9000ce3f598 R11: ffffffff81acf3d0 R12: 1ffff920019c7ea9
R13: ffffc9000ce3f598 R14: ffffc9000ce3f548 R15: ffffffff8173fd65
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
alloc_empty_file+0x55/0x1d0 fs/file_table.c:237
path_openat+0x108/0x3dd0 fs/namei.c:4773
do_filp_open+0x1fa/0x410 fs/namei.c:4814
do_sys_openat2+0x121/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa495aa7407
RSP: 002b:00007fff5f9a9980 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa49629a880 RCX: 00007fa495aa7407
RDX: 0000000000080000 RSI: 000055ac839458a0 RDI: ffffffffffffff9c
RBP: 000055ac83951f10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff5f9ba140
R13: 00007fff5f9ba3a0 R14: 00007fff5f9ba7a0 R15: 000055ac56a8bbcc
rcu: rcu_preempt kthread starved for 10502 jiffies! g207701 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:27480 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 25493 Comm: syz.2.4480 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 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 73 93
RSP: 0018:ffffc90014cf70e0 EFLAGS: 00000246
RAX: ffffffff81b5644d RBX: 1ffff110170c856d RCX: 0000000000080000
RDX: ffffc90017563000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90014cf7210 R08: ffffffff8f822177 R09: 1ffffffff1f0442e
R10: dffffc0000000000 R11: fffffbfff1f0442f R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
FS: 00007f75f7dbb6c0(0000) GS:ffff888125f21000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001a7030 CR3: 00000000ae3e6000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:103
wp_page_copy mm/memory.c:3785 [inline]
do_wp_page+0x1bb1/0x5810 mm/memory.c:4180
handle_pte_fault mm/memory.c:6289 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580
do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 97 6d 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90014cf78b8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000026a030
RDX: ffff888030b4db80 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90014cf7a30 R08: ffffc90014cf7667 R09: 1ffff9200299eecc
R10: dffffc0000000000 R11: fffff5200299eecd R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000000 R15: 000020000026a000
____sys_recvmsg+0x2ab/0x460 net/socket.c:2825
___sys_recvmsg+0x1b5/0x510 net/socket.c:2854
do_recvmmsg+0x307/0x770 net/socket.c:2949
__sys_recvmmsg net/socket.c:3023 [inline]
__do_sys_recvmmsg net/socket.c:3046 [inline]
__se_sys_recvmmsg net/socket.c:3039 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3039
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75f6f8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f75f7dbb038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f75f71e6090 RCX: 00007f75f6f8f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f75f7013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75f71e6128 R14: 00007f75f71e6090 R15: 00007f75f730fa28