rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5829/1:b..l P5206/1:b..l P11295/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=45953, q=1255 ncpus=2)
task:syz.3.1364 state:R running task stack:27672 pid:11295 tgid:11295 ppid:5843 task_flags:0x40044c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x70 kernel/kcov.c:217
Code: 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 65 48 8b 15 f8 0c 1a 12 65 8b 05 09 0d 1a 12 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00
RSP: 0018:ffffc9000c9b7480 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 00000000000669ae RCX: ffffffff822d83d1
RDX: ffff88802bb98000 RSI: ffffffff822d8455 RDI: 0000000000000006
RBP: ffff88813fffa580 R08: 0000000000000006 R09: 0000000000001000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000180
R13: ffff88823ffef400 R14: 0000000000000000 R15: ffffea00019a6b80
lookup_page_ext+0xe5/0x1d0 mm/page_ext.c:252
page_ext_get+0x58/0x1a0 mm/page_ext.c:528
__reset_page_owner+0x2b/0x1a0 mm/page_owner.c:294
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
free_unref_folios+0xa61/0x16b0 mm/page_alloc.c:2952
folios_put_refs+0x56f/0x740 mm/swap.c:997
free_pages_and_swap_cache+0x245/0x4a0 mm/swap_state.c:264
__tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu mm/mmu_gather.c:404 [inline]
tlb_finish_mmu+0x168/0x7c0 mm/mmu_gather.c:497
exit_mmap+0x403/0xb90 mm/mmap.c:1293
__mmput+0x12a/0x410 kernel/fork.c:1126
mmput+0x62/0x70 kernel/fork.c:1149
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:949
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f743c7c1425
RSP: 002b:00007f743d607f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f743c9b5fa0 RCX: 00007f743c7c1425
RDX: 00007f743d607fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f743c811df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f743c9b5fa0 R15: 00007ffd1de452f8
task:klogd state:R running task stack:25512 pid:5206 tgid:5206 ppid:1 task_flags:0x400100 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194
sock_def_readable+0x15b/0x600 net/core/sock.c:3564
unix_dgram_sendmsg+0xd1b/0x17f0 net/unix/af_unix.c:2309
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
__sys_sendto+0x4a3/0x520 net/socket.c:2228
__do_sys_sendto net/socket.c:2235 [inline]
__se_sys_sendto net/socket.c:2231 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2231
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc1ed608407
RSP: 002b:00007ffda7945920 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fc1ed4b8c80 RCX: 00007fc1ed608407
RDX: 000000000000005f RSI: 00007ffda7945a60 RDI: 0000000000000003
RBP: 00007ffda7945e90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffda7945ea8
R13: 00007ffda7945a60 R14: 0000000000000044 R15: 00007ffda7945a60
task:syz-executor state:R running task stack:23368 pid:5829 tgid:5829 ppid:5828 task_flags:0x400100 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x15/0x350 kernel/locking/lockdep.c:5828
Code: 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 41 57 4d 89 cf 41 56 41 89 f6 41 55 41 89 d5 41 54 <45> 89 c4 55 89 cd 53 48 89 fb 48 83 ec 38 65 48 8b 05 4d d7 3d 12
RSP: 0018:ffffc90003d9f8f0 EFLAGS: 00000246
RAX: ffffffff816ae56d RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e5c1160
RBP: ffffc90003d9f9d8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000000a6e0 R12: ffffffff81a6dd50
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
discard_slab mm/slub.c:2753 [inline]
__put_partials+0x165/0x1c0 mm/slub.c:3218
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4236
alloc_empty_file+0x55/0x1e0 fs/file_table.c:237
alloc_file fs/file_table.c:354 [inline]
alloc_file_clone+0x5f/0x110 fs/file_table.c:432
create_pipe_files+0x412/0x9a0 fs/pipe.c:954
__do_pipe_flags fs/pipe.c:988 [inline]
do_pipe2+0xaf/0x1c0 fs/pipe.c:1036
__do_sys_pipe2 fs/pipe.c:1054 [inline]
__se_sys_pipe2 fs/pipe.c:1052 [inline]
__x64_sys_pipe2+0x54/0x80 fs/pipe.c:1052
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f20d9f8d889
RSP: 002b:00007ffcdf1caee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000125
RAX: ffffffffffffffda RBX: 00005555751de950 RCX: 00007f20d9f8d889
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 00007ffcdf1caf00
RBP: 00007ffcdf1cb2b0 R08: 0000000000000007 R09: 00005555751e0bb0
R10: 33f94079fa0238b1 R11: 0000000000000246 R12: 00005555751deb20
R13: 00005555751e31c8 R14: 00007ffcdf1cb030 R15: 00005555751e4580
rcu: rcu_preempt kthread starved for 8147 jiffies! g45953 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d7/0x6f0 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:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller-11699-g7e161a991ea7 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 5c 63 02 c3 cc cc cc cc 0f 1f 00 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 f3 92 17 00 fb f4 4c 0d 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2
RAX: 00000000031018db RBX: 0000000000000001 RCX: ffffffff8b927c29
RDX: 0000000000000000 RSI: ffffffff8de4d213 RDI: ffffffff8c160d00
RBP: ffffed1003c56488 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e2b2440 R14: ffffffff90aaec90 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881247c6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe41780d38 CR3: 000000000e380000 CR4: 00000000003526f0
DR0: 000000000000fffe DR1: 0000000000000003 DR2: 0000000000000e8f
DR3: 0000000000000007 DR6: 00000000ffff0ff0 DR7: 0000000000000400
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+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148