rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12829/1:b..l P12765/1:b..l P12905/1:b..l P12341/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=68873, q=1266 ncpus=2)
task:syz-executor state:R running task stack:20288 pid:12341 tgid:12341 ppid:12331 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
vprintk_emit+0x53b/0x5f0 kernel/printk/printk.c:2427
_printk+0xcf/0x120 kernel/printk/printk.c:2451
_btrfs_printk+0x562/0x5b0 fs/btrfs/messages.c:250
btrfs_put_super+0x113/0x1b0 fs/btrfs/super.c:73
generic_shutdown_super+0x135/0x2c0 fs/super.c:643
kill_anon_super+0x3b/0x70 fs/super.c:1289
btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2129
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
task_work_run+0x1d4/0x260 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:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__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_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c02b90a77
RSP: 002b:00007fff1e83f278 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f9c02b90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff1e83f330
RBP: 00007fff1e83f330 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff1e8403c0
R13: 00007f9c02c13d7d R14: 00000000000b8b79 R15: 00007fff1e840400
task:dhcpcd-run-hook state:R running task stack:24864 pid:12905 tgid:12905 ppid:12859 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 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:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000b057438 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffffffff81743fa2 RCX: 29ca10f9cf997500
RDX: 0000000000000000 RSI: ffffffff81743fa2 RDI: 1ffffffff1be834c
RBP: ffffffff81743f85 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000b057618 R11: ffffffff81ada980 R12: 0000000000000002
R13: ffffffff8df41a60 R14: ffffffff8df41a60 R15: 0000000000000000
__kasan_check_byte+0x12/0x40 mm/kasan/common.c:573
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
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
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2492 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x16b/0x620 mm/slub.c:6781
exit_mmap+0x52c/0xb10 mm/mmap.c:1302
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 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: 0033:0x7fc652e586c5
RSP: 002b:00007ffe554a05d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffe554a0804 RCX: 00007fc652e586c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007ffe554a06d0 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffe554a0910 R14: 00007fc653068000 R15: 000055f8e4831d98
task:syz.0.1537 state:R running task stack:20192 pid:12765 tgid:12765 ppid:5824 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 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:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217
Code: 5b e9 b3 32 5b 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 f0 7e 92 <65> 8b 15 c8 38 bd 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90004766798 EFLAGS: 00000246
RAX: ffffffff8b553e92 RBX: 000000000000000f RCX: ffff888025a3bd00
RDX: 0000000000000000 RSI: 00007f9c697f7fff RDI: 00007f9c697f7fff
RBP: dffffc0000000000 R08: ffff888025a3bd00 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888038612208
R13: 00007f9c697f7fff R14: 00007f9c697f7fff R15: ffff888038612200
ma_data_end lib/maple_tree.c:1260 [inline]
mtree_range_walk+0x622/0x840 lib/maple_tree.c:2558
mas_state_walk lib/maple_tree.c:3298 [inline]
mt_find+0x244/0x5e0 lib/maple_tree.c:6497
find_vma+0xe7/0x160 mm/mmap.c:906
gup_vma_lookup mm/gup.c:1275 [inline]
__get_user_pages+0x3ae/0x29f0 mm/gup.c:1396
__get_user_pages_locked mm/gup.c:1692 [inline]
get_dump_page+0x1ac/0x3f0 mm/gup.c:2192
dump_user_range+0x1de/0xc90 fs/coredump.c:1366
elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111
coredump_write+0x1121/0x18b0 fs/coredump.c:1049
do_coredump fs/coredump.c:1126 [inline]
vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200
get_signal+0x1108/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x177/0x660 kernel/entry/common.c:196
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f9c6b58f751
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f9c6b7e5fa0 RCX: 00007f9c6b58f749
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f9c6b613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f9c6b7e6038 R14: 00007f9c6b7e5fa0 R15: 00007ffd7d736f18
task:syz.7.1549 state:R running task stack:25336 pid:12829 tgid:12828 ppid:11054 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
vprintk_emit+0x53b/0x5f0 kernel/printk/printk.c:2427
_printk+0xcf/0x120 kernel/printk/printk.c:2451
_btrfs_printk+0x562/0x5b0 fs/btrfs/messages.c:250
btrfs_fill_super fs/btrfs/super.c:985 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1946 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2089 [inline]
btrfs_get_tree+0x13ec/0x1920 fs/btrfs/super.c:2123
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x302/0xa10 fs/namespace.c:3712
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4201
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: 0033:0x7f8885190eea
RSP: 002b:00007f8885fdae68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8885fdaef0 RCX: 00007f8885190eea
RDX: 00002000000055c0 RSI: 0000200000005600 RDI: 00007f8885fdaeb0
RBP: 00002000000055c0 R08: 00007f8885fdaef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000005600
R13: 00007f8885fdaeb0 R14: 000000000000559a R15: 0000200000000040
rcu: rcu_preempt kthread starved for 10678 jiffies! g68873 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 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+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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
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 13 50 0c 00 f3 0f 1e fa fb f4 c8 ed 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: aef9e7c2dd7b8d00 RBX: ffffffff8197983a RCX: aef9e7c2dd7b8d00
RDX: 0000000000000001 RSI: ffffffff8d7939c1 RDI: ffffffff8bc08360
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822a70
R13: 1ffff11003a51b70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125f31000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000009000 CR3: 000000007597e000 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