rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7861/1:b..l P7853/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=24373, q=29512 ncpus=2)
task:syz.5.421 state:R running task stack:25400 pid:7853 tgid:7853 ppid:6992 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1884 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x3c17/0x44e0 mm/memory.c:2017
unmap_single_vma mm/memory.c:2059 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2101
exit_mmap+0x239/0xb10 mm/mmap.c:1277
__mmput+0x118/0x430 kernel/fork.c:1177
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x850/0x25b0 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb96998f749
RSP: 002b:00007ffd892c9838 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007fb96998f749
RDX: 00007fb969946c47 RSI: 0000000000000000 RDI: 000000000000000b
RBP: 0000000000000003 R08: 00007ffd892c9cd7 R09: 000000000000000b
R10: 00007fb969be5fa0 R11: 0000000000000246 R12: 00007fb969be627c
R13: 00007fb969be6270 R14: 000000000000025e R15: 0000000000000005
task:syz-executor state:R running task stack:26744 pid:7861 tgid:7861 ppid:5830 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
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:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x58/0x340 kernel/locking/lockdep.c:5831
Code: 8b 05 7c 42 01 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 7f 42 01 11 83 f8 08 0f 83 af 01 00 00 89 c0 48 0f a3 05 a8 c1 03 0e <73> 0d e8 c1 29 09 00 84 c0 0f 84 d7 01 00 00 83 3d c2 f1 03 0e 00
RSP: 0018:ffffc90003537090 EFLAGS: 00000297
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e13f2e0
RBP: ffffffff81d0f976 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003537218 R11: ffffffff81ad9d50 R12: 0000000000000002
R13: ffffffff8e13f2e0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
is_bpf_text_address+0x47/0x2b0 kernel/bpf/core.c:747
kernel_text_address+0xa5/0xe0 kernel/extable.c:125
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
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:5267 [inline]
kmem_cache_alloc_lru_noprof+0x36c/0x6e0 mm/slub.c:5286
proc_alloc_inode+0x2a/0xc0 fs/proc/inode.c:57
alloc_inode+0x6a/0x1b0 fs/inode.c:346
new_inode+0x22/0x170 fs/inode.c:1175
proc_pid_make_inode+0x21/0x130 fs/proc/base.c:1953
proc_pid_make_base_inode fs/proc/base.c:2004 [inline]
proc_pid_instantiate+0x53/0x2b0 fs/proc/base.c:3486
proc_pid_lookup+0x2fa/0x420 fs/proc/base.c:3529
proc_root_lookup+0x20/0x50 fs/proc/root.c:405
__lookup_slow+0x297/0x3d0 fs/namei.c:1858
lookup_slow+0x53/0x70 fs/namei.c:1875
walk_component fs/namei.c:2221 [inline]
link_path_walk+0x1273/0x18d0 fs/namei.c:2586
path_openat+0x2b0/0x3840 fs/namei.c:4782
do_filp_open+0x1fa/0x410 fs/namei.c:4813
do_sys_openat2+0x121/0x200 fs/open.c:1391
do_sys_open fs/open.c:1397 [inline]
__do_sys_openat fs/open.c:1413 [inline]
__se_sys_openat fs/open.c:1408 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1408
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f773458df90
RSP: 002b:00007ffd0b74cc20 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000080001 RCX: 00007f773458df90
RDX: 0000000000080001 RSI: 00007f77346158aa RDI: 00000000ffffff9c
RBP: 00007f77346158aa R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007ffd0b74ccc0 R14: 0000000000038011 R15: 00007ffd0b74d230
rcu: rcu_preempt kthread starved for 10588 jiffies! g24373 f0x2 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:27728 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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+0x599/0xb30 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: 0 Comm: swapper/1 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:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 9e 2a 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 7a2adb544d831b00 RBX: ffffffff819786ba RCX: 7a2adb544d831b00
RDX: 0000000000000001 RSI: ffffffff8d997e54 RDI: ffffffff8be07960
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fa22f70
R13: 1ffff11003adfb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf0f796f98 CR3: 0000000060ab0000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147