rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7952/1:b..l P6049/1:b..l P7947/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=26397, q=736 ncpus=2)
task:syz.8.259 state:R running task stack:24584 pid:7947 tgid:7947 ppid:7558 task_flags:0x400040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7148
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7172
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]
insert_page+0x189/0x2c0 mm/memory.c:2333
kcov_mmap+0xc2/0x120 kernel/kcov.c:506
vfs_mmap include/linux/fs.h:2283 [inline]
mmap_file mm/internal.h:167 [inline]
__mmap_new_file_vma mm/vma.c:2413 [inline]
__mmap_new_vma mm/vma.c:2476 [inline]
__mmap_region mm/vma.c:2669 [inline]
mmap_region+0x18a8/0x2100 mm/vma.c:2739
do_mmap+0xc45/0x10d0 mm/mmap.c:558
vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580
ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f25f7f8ec23
RSP: 002b:00007ffe9c68afb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f25f81c6308 RCX: 00007f25f7f8ec23
RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f25f5df6000
RBP: 00007f25f81c6270 R08: 00000000000000db R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f25f81c6270 R14: 0000000000001cb3 R15: 0000000000000004
task:udevd state:R running task stack:23488 pid:6049 tgid:6049 ppid:5234 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x9/0x3e0 kernel/locking/lockdep.c:5876
Code: 24 e9 08 fa ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 <41> 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 c0 f6 23
RSP: 0018:ffffc90003d8ea18 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff90541001 RCX: a02a7935f3e67000
RDX: ffffc90003d8eb01 RSI: ffffffff8173bcb5 RDI: ffffffff8e33cf20
RBP: dffffc0000000000 R08: ffffc90003d8eb58 R09: 0000000000000000
R10: ffffc90003d8ebb8 R11: fffff520007b1d79 R12: ffffc90003d8eb68
R13: ffffc90003d88000 R14: ffffc90003d8eb68 R15: ffffffff8173bcb5
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x4a0 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3863
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5153
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
folio_alloc_mpol_noprof mm/mempolicy.c:2435 [inline]
vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2470
folio_prealloc+0x30/0x180 mm/memory.c:-1
alloc_anon_folio mm/memory.c:5125 [inline]
do_anonymous_page mm/memory.c:5182 [inline]
do_pte_missing mm/memory.c:4360 [inline]
handle_pte_fault mm/memory.c:6182 [inline]
__handle_mm_fault+0x2a8b/0x5400 mm/memory.c:6323
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6492
do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74
Code: cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 a4 e9 ff 28 04 00 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48
RSP: 0018:ffffc90003d8f7d8 EFLAGS: 00050206
RAX: ffffffff84c89101 RBX: ffff888061f09000 RCX: 0000000000001000
RDX: 0000000000000000 RSI: ffff888061f09000 RDI: 00007f434ddde000
RBP: ffffc90003d8f948 R08: ffff888061f09fff R09: 1ffff1100c3e13ff
R10: dffffc0000000000 R11: ffffed100c3e1400 R12: 1ffff920007b1faf
R13: 00007f434ddde000 R14: ffffc90003d8fd88 R15: 0000000000001000
copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
copy_to_user_iter lib/iov_iter.c:25 [inline]
iterate_ubuf include/linux/iov_iter.h:30 [inline]
iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
iterate_and_advance include/linux/iov_iter.h:330 [inline]
_copy_to_iter+0x24f/0x1790 lib/iov_iter.c:185
copy_page_to_iter+0x10c/0x1c0 lib/iov_iter.c:362
copy_folio_to_iter include/linux/uio.h:204 [inline]
filemap_read+0x7c0/0x11a0 mm/filemap.c:2781
blkdev_read_iter+0x30a/0x440 block/fops.c:852
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x557/0xa30 fs/read_write.c:572
ksys_read+0x145/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f434d6a7407
RSP: 002b:00007ffe9d68af10 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f434de25880 RCX: 00007f434d6a7407
RDX: 0000000000040000 RSI: 00007f434ddbd000 RDI: 0000000000000009
RBP: 0000557a908e2050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000557a908d5218 R15: 00007f434df4c39c
task:syz.8.259 state:R running task stack:27208 pid:7952 tgid:7947 ppid:7558 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg+0x63/0x230 arch/x86/kernel/unwind_orc.c:403
Code: 48 89 df e8 5f e9 b0 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 48 89 5c 24 10 49 8b 5f 08 4d 8d 77 10 4d 89 f5 49 c1 ed 03 <41> 80 7c 35 00 00 74 16 4c 89 f7 e8 2d e9 b0 00 4c 8b 04 24 48 be
RSP: 0018:ffffc9000b6975a0 EFLAGS: 00000a06
RAX: fffffffffffffff0 RBX: ffffc9000b690000 RCX: 0000000000000000
RDX: ffffc9000b697708 RSI: dffffc0000000000 RDI: ffffc9000b6976c8
RBP: dffffc0000000000 R08: ffffc9000b697cc8 R09: 0000000000000000
R10: ffffc9000b697718 R11: fffff520016d2ee5 R12: 1ffff920016d2eda
R13: 1ffff920016d2edb R14: ffffc9000b6976d8 R15: ffffc9000b6976c8
unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1
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:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5397
kmalloc_noprof include/linux/slab.h:956 [inline]
kzalloc_noprof include/linux/slab.h:1090 [inline]
ipv4_sysctl_init_net+0x2af/0x3f0 net/ipv4/sysctl_net_ipv4.c:1631
ops_init+0x35c/0x5c0 net/core/net_namespace.c:136
setup_net+0x10c/0x320 net/core/net_namespace.c:438
copy_net_ns+0x31b/0x4d0 net/core/net_namespace.c:570
create_new_namespaces+0x3f3/0x720 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:218
ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3140
__do_sys_unshare kernel/fork.c:3211 [inline]
__se_sys_unshare kernel/fork.c:3209 [inline]
__x64_sys_unshare+0x38/0x50 kernel/fork.c:3209
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f25f7f8ebe9
RSP: 002b:00007f25f8e6e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f25f81c5fa0 RCX: 00007f25f7f8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200
RBP: 00007f25f8011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f25f81c6038 R14: 00007f25f81c5fa0 R15: 00007ffe9c68aef8
rcu: rcu_preempt kthread starved for 10627 jiffies! g26397 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:26504 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
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+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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 61 29 00 f3 0f 1e fa fb f4 08 e7 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8e007d80 EFLAGS: 000002c6
RAX: 9cd92ed561de6600 RBX: ffffffff81978e38 RCX: 9cd92ed561de6600
RDX: 0000000000000001 RSI: ffffffff8dbbd436 RDI: ffffffff8c037200
RBP: ffffffff8e007ea8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3
R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fc3ee30
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c12a38
FS: 0000000000000000(0000) GS:ffff8881259f9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faa484c2d58 CR3: 0000000068a4e000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:756
start_kernel+0x3a9/0x410 init/main.c:1109
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x147