INFO: rcu detected stall in mntput_no

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.1	INFO: rcu detected stall in mntput_no_expire	1				1	279d	279d	0/3	auto-obsoleted due to no activity on 2026/02/15 08:46
linux-5.15	INFO: rcu detected stall in mntput_no_expire	1				1	810d	810d	0/3	auto-obsoleted due to no activity on 2024/09/02 16:00
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6198/1:b..l P5193/1:b..l P6186/1:b..l P6190/1:b..l P12/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=12177, q=1049 ncpus=2)
task:kworker/u8:0    state:R  running task     stack:24568 pid:12    tgid:12    ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: bat_events batadv_mcast_mla_update
Call Trace:
 <TASK>
 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+0x5e3/0x670 kernel/entry/common.c:216
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:228 [inline]
RIP: 0010:unwind_next_frame+0x214/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: ef 08 8b 15 7e f4 26 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 00 20 c2 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 2c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d
RSP: 0018:ffffc900001173b8 EFLAGS: 00000213
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000000
RDX: 00000000000a5d62 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: dffffc0000000000 R08: ffffffff8173fd65 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffffff81acf3d0 R12: ffffffff81331fa9
R13: ffffffff90c2ec7c R14: ffffc90000117488 R15: 000000000000331f
 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
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6670 [inline]
 kfree+0x1c0/0x660 mm/slub.c:6878
 batadv_mcast_mla_list_free net/batman-adv/multicast.c:667 [inline]
 __batadv_mcast_mla_update net/batman-adv/multicast.c:924 [inline]
 batadv_mcast_mla_update+0x3398/0x3640 net/batman-adv/multicast.c:946
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 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
 </TASK>
task:syz.5.44        state:R  running task     stack:25984 pid:6190  tgid:6189  ppid:5840   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 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+0x5e3/0x670 kernel/entry/common.c:216
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 20 b1 bb 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0a 20 e2 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 da 50 72 ff cc 48 8d 3d 37 78 e7
RSP: 0018:ffffc9000b887418 EFLAGS: 00000286
RAX: e183e9ebaf7f2700 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000005a44979c RSI: ffffffff8d976049 RDI: ffffffff8bc08360
RBP: ffffffff8173fd65 R08: ffffffff8173fd65 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffffff81acf3d0 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]
 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]
 __do_kmalloc_node mm/slub.c:5657 [inline]
 __kvmalloc_node_noprof+0x5d5/0x920 mm/slub.c:7136
 kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
 alloc_fdtable+0x101/0x2c0 fs/file.c:219
 dup_fd+0x84f/0xb40 fs/file.c:420
 copy_files+0xc9/0x120 kernel/fork.c:1635
 copy_process+0x1513/0x3950 kernel/fork.c:2209
 kernel_clone+0x21e/0x820 kernel/fork.c:2651
 __do_sys_clone kernel/fork.c:2792 [inline]
 __se_sys_clone kernel/fork.c:2776 [inline]
 __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
 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: 0033:0x7f53cd18f749
RSP: 002b:00007f53ce06cfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f53cd3e5fa0 RCX: 00007f53cd18f749
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f53cd213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f53cd3e6038 R14: 00007f53cd3e5fa0 R15: 00007fff9394ca78
 </TASK>
task:syz.4.28        state:R  running task     stack:25856 pid:6186  tgid:6180  ppid:5821   task_flags:0x40044c flags:0x00080001
Call Trace:
 <TASK>
 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+0x5e3/0x670 kernel/entry/common.c:216
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:unwind_next_frame+0x1a66/0x23d0 arch/x86/kernel/unwind_orc.c:695
Code: c6 03 01 4c 8b 7c 24 50 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 35 02 00 00 41 c7 06 00 00 00 00 31 db e8 6c 8f e5 09 85 c0 <74> 3a e8 a3 e5 32 00 84 c0 75 31 e8 5a 8f e5 09 85 c0 74 28 80 3d
RSP: 0018:ffffc900054b6d78 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff9025b101 RCX: ffff888026ca1e80
RDX: ffffc900054b6e01 RSI: dffffc0000000000 RDI: ffffc900054b6e50
RBP: dffffc0000000000 R08: ffffc900054b7968 R09: ffffc900054b6e98
R10: dffffc0000000000 R11: fffff52000a96dd5 R12: ffffc900054b7978
R13: ffffc900054b0000 R14: ffffc900054b6e48 R15: ffffffff8173fd65
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:165
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1406 [inline]
 free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:3000
 folios_put_refs+0x584/0x670 mm/swap.c:1002
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x49e/0x1490 mm/shmem.c:1137
 shmem_truncate_range mm/shmem.c:1249 [inline]
 shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379
 evict+0x5f4/0xae0 fs/inode.c:837
 __dentry_kill+0x209/0x660 fs/dcache.c:670
 finish_dput+0xc9/0x480 fs/dcache.c:879
 __fput+0x68e/0xa70 fs/file_table.c:476
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x694/0x22f0 kernel/exit.c:971
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 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+0x87/0x4e0 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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd411f8f749
RSP: 002b:00007fd412daa0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fd4121e6098 RCX: 00007fd411f8f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd4121e6098
RBP: 00007fd4121e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd4121e6128 R14: 00007ffc5ad893d0 R15: 00007ffc5ad894b8
 </TASK>
task:udevd           state:R  running task     stack:25048 pid:5193  tgid:5193  ppid:1      task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 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+0x5e3/0x670 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d8/0x3b0 kernel/locking/lockdep.c:5893
Code: 34 e2 10 00 00 00 00 eb b5 e8 84 7f bb 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 74 ee e1 10 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 44 1f 72 ff cc 48 8d 3d 11 4a e7
RSP: 0018:ffffc90003677d28 EFLAGS: 00000286
RAX: ddd65895e27a0400 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8d976049 RDI: ffffffff8bc08360
RBP: ffff88807cb10b30 R08: ffffffff8241ecfc R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffed100a8be6d9 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8df41aa0 R15: ffff88807cb10000
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 mntput_no_expire+0x190/0x1c0 fs/namespace.c:1409
 __fput+0x6ba/0xa70 fs/file_table.c:479
 fput_close_sync+0x113/0x220 fs/file_table.c:573
 __do_sys_close fs/open.c:1573 [inline]
 __se_sys_close fs/open.c:1558 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1558
 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: 0033:0x7f6dcff15a67
RSP: 002b:00007fffd3fc5518 EFLAGS: 00000206 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 000056425ab11a20 RCX: 00007f6dcff15a67
RDX: 0000000000013ea1 RSI: 00007f6dcfff1b20 RDI: 000000000000000d
RBP: 000056425aaa19d0 R08: 000000000000be60 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000206 R12: 000056425aa957b0
R13: 00000000000000ff R14: 0000564241dbfbe0 R15: 00007fffd3fc5790
 </TASK>
task:syz.2.47        state:R  running task     stack:27032 pid:6198  tgid:6197  ppid:5822   task_flags:0x40044c flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
 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+0x38bc/0x4170 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:1173
 exit_mm+0x169/0x230 kernel/exit.c:581
 do_exit+0x627/0x22f0 kernel/exit.c:959
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 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+0x87/0x4e0 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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc44a58f749
RSP: 002b:00007fc44b4470e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fc44a7e5fa8 RCX: 00007fc44a58f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fc44a7e5fac
RBP: 00007fc44a7e5fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc44a7e6038 R14: 00007ffc0d0a5600 R15: 00007ffc0d0a56e8
 </TASK>
rcu: rcu_preempt kthread starved for 10485 jiffies! g12177 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:27576 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
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: 1e a4 b6 f5 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 53 b1 0e 00 f3 0f 1e fa fb f4 <e9> f3 a3 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c6
RAX: 00000000001177df RBX: ffffffff819713ee RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d792135 RDI: ffffffff8bc08360
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822370
R13: 1ffff1100385fb70 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e97856cb9 CR3: 000000002dea4000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 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+0x1be/0x4d0 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
 </TASK>