Re: [PATCH] mm/vmalloc: fix vmap_purge_lock livelock under memory pressure

[Dev Jain]

On 25/08/26 11:10 pm, Uladzislau Rezki wrote:
> On Tue, Aug 25, 2026 at 09:04:24AM +0800, Ye Liu wrote:
>>
>>
>> 在 2026/8/24 21:19, Uladzislau Rezki 写道:
>>> On Mon, Aug 24, 2026 at 05:50:19PM +0800, Ye Liu wrote:
>>>> From: Ye Liu <liuye@xxxxxxxxxx>
>>>>
>>>> The vmap_purge_lock mutex can be held for an extended period by
>>>> __purge_vmap_area_lazy() which calls flush_work() to wait for
>>>> purge_vmap_node workers while holding the lock.  Under memory
>>>> pressure, those workers may themselves be blocked in direct
>>>> reclaim trying to acquire the same lock via the
>>>> vmap_node_shrink_scan() shrinker callback, creating a circular
>>>> dependency that deadlocks the entire system.
>>>>
>>>> Two changes:
>>>>
>>>> 1. vmap_node_shrink_scan(): replace blocking guard(mutex) with
>>>>    mutex_trylock().  This is a shrinker that only decays the vmap
>>>>    pool and returns SHRINK_STOP without freeing memory; skipping a
>>>>    decay cycle when the lock is contended is harmless and prevents
>>>>    tasks from piling up on the mutex in the direct reclaim path.
>>>>
>>>> 2. __purge_vmap_area_lazy(): purge all vmap nodes inline instead of
>>>>    scheduling purge_vmap_node via workqueue and calling flush_work()
>>>>    while holding vmap_purge_lock.  The workqueue dispatch + flush
>>>>    pattern under a mutex is the deadlock trigger: if no free worker
>>>>    threads are available (all blocked on the same lock), flush_work()
>>>>    never returns and the lock is held indefinitely.
>>>>
>>>> Fixes: 7679ba6b36db ("mm: vmalloc: add a shrinker to drain vmap pools")
>>>> Signed-off-by: Ye Liu <liuye@xxxxxxxxxx>
>>>> ---
>>>>  mm/vmalloc.c | 51 +++++++++++++++++++++------------------------------
>>>>  1 file changed, 21 insertions(+), 30 deletions(-)
>>>>
>>>> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
>>>> index bea9f76ed7e7..41443708d22d 100644
>>>> --- a/mm/vmalloc.c
>>>> +++ b/mm/vmalloc.c
>>>> @@ -2358,7 +2358,6 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end,
>>>>  		bool full_pool_decay)
>>>>  {
>>>>  	unsigned long nr_purged_areas = 0;
>>>> -	unsigned int nr_purge_helpers;
>>>>  	static cpumask_t purge_nodes;
>>>>  	unsigned int nr_purge_nodes;
>>>>  	struct vmap_node *vn;
>>>> @@ -2397,36 +2396,17 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end,
>>>>  	if (nr_purge_nodes > 0) {
>>>>  		flush_tlb_kernel_range(start, end);
>>>>  
>>>> -		/* One extra worker is per a lazy_max_pages() full set minus one. */
>>>> -		nr_purge_helpers = atomic_long_read(&vmap_lazy_nr) / lazy_max_pages();
>>>> -		nr_purge_helpers = clamp(nr_purge_helpers, 1U, nr_purge_nodes) - 1;
>>>> -
>>>> -		for_each_cpu(i, &purge_nodes) {
>>>> -			vn = &vmap_nodes[i];
>>>> -
>>>> -			if (nr_purge_helpers > 0) {
>>>> -				INIT_WORK(&vn->purge_work, purge_vmap_node);
>>>> -
>>>> -				if (cpumask_test_cpu(i, cpu_online_mask))
>>>> -					schedule_work_on(i, &vn->purge_work);
>>>> -				else
>>>> -					schedule_work(&vn->purge_work);
>>>> -
>>>> -				nr_purge_helpers--;
>>>> -			} else {
>>>> -				vn->purge_work.func = NULL;
>>>> -				purge_vmap_node(&vn->purge_work);
>>>> -				nr_purged_areas += vn->nr_purged;
>>>> -			}
>>>> -		}
>>>> -
>>>> +		/*
>>>> +		 * Purge all nodes inline.  Do not schedule_work() and
>>>> +		 * flush_work() here: flush_work() while holding
>>>> +		 * vmap_purge_lock can deadlock if the worker pool is
>>>> +		 * starved (e.g. all workers blocked on this same lock
>>>> +		 * in the direct reclaim path via vmap_node_shrink_scan).
>>>> +		 */
>>>>  		for_each_cpu(i, &purge_nodes) {
>>>>  			vn = &vmap_nodes[i];
>>>> -
>>>> -			if (vn->purge_work.func) {
>>>> -				flush_work(&vn->purge_work);
>>>> -				nr_purged_areas += vn->nr_purged;
>>>> -			}
>>>> +			purge_vmap_node(&vn->purge_work);
>>>> +			nr_purged_areas += vn->nr_purged;
>>>>  		}
>>>>  	}
>>>>  
>>>> @@ -5519,10 +5499,21 @@ vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
>>>>  {
>>>>  	struct vmap_node *vn;
>>>>  
>>>> -	guard(mutex)(&vmap_purge_lock);
>>>> +	/*
>>>> +	 * This shrinker is invoked from direct reclaim path where memory
>>>> +	 * pressure is already high.  Blocking on vmap_purge_lock here can
>>>> +	 * cause a pile-up of tasks all waiting for the same mutex while
>>>> +	 * the lock holder may itself be blocked in flush_work() waiting for
>>>> +	 * a worker that is stuck in the same reclaim path.  Use trylock to
>>>> +	 * avoid this; skipping a pool decay cycle is harmless.
>>>> +	 */
>>>> +	if (!mutex_trylock(&vmap_purge_lock))
>>>> +		return SHRINK_STOP;
>>>> +
>>>>  	for_each_vmap_node(vn)
>>>>  		decay_va_pool_node(vn, true);
>>>>  
>>>> +	mutex_unlock(&vmap_purge_lock);
>>>>  	return SHRINK_STOP;
>>>>  }
>>>>  
>>>> -- 
>>>> 2.25.1
>>>>
>>> Have you seen any report about the problem you described?
>>>
>> Our testing team discovered the issue during testing with syzkaller 
>> on kernel version 6.6.89. The relevant warnings are shown below.
>>
>> INFO: task kworker/u80:6:141 blocked for more than 143 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:kworker/u80:6 state:D stack:0 pid:141 tgid:141 ppid:2 flags:0x00004000
>> Workqueue: events_unbound call_usermodehelper_exec_work
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> __alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:244 [inline]
>> alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:271 [inline]
>> alloc_thread_stack_node root/klinux/kernel/fork.c:367 [inline]
>> dup_task_struct+0xa4/0x6c0 root/klinux/kernel/fork.c:1161
>> copy_process+0x4eb/0x57d0 root/klinux/kernel/fork.c:2261
>> kernel_clone+0xdd/0x910 root/klinux/kernel/fork.c:2849
>> user_mode_thread+0xcb/0x110 root/klinux/kernel/fork.c:2927
>> call_usermodehelper_exec_sync root/klinux/kernel/umh.c:133 [inline]
>> call_usermodehelper_exec_work+0x69/0x170 root/klinux/kernel/umh.c:164
>> process_one_work+0x90d/0x1aa0 root/klinux/kernel/workqueue.c:3235
>> process_scheduled_works root/klinux/kernel/workqueue.c:3315 [inline]
>> worker_thread+0x633/0xe80 root/klinux/kernel/workqueue.c:3396
>> kthread+0x317/0x420 root/klinux/kernel/kthread.c:388
>> ret_from_fork+0x4ae/0x5e0 root/klinux/arch/x86/kernel/process.c:152
>> ret_from_fork_asm+0x1a/0x30 root/klinux/arch/x86/entry/entry_64.S:293
>>
>> INFO: task syz-executor.0:37820 blocked for more than 143 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:syz-executor.0 state:D stack:0 pid:37820 tgid:37820 ppid:1 flags:0x00000004
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> alloc_pages_mpol_noprof+0x1ee/0x530 root/klinux/mm/mempolicy.c:2270
>> pagetable_alloc_noprof root/klinux/./include/linux/mm.h:2982 [inline]
>> __pud_alloc_one_noprof root/klinux/./include/asm-generic/pgalloc.h:174 [inline]
>> pud_alloc_one_noprof root/klinux/./include/asm-generic/pgalloc.h:195 [inline]
>> __pud_alloc+0x40/0x650 root/klinux/mm/memory.c:6222
>> pud_alloc root/klinux/./include/linux/mm.h:2939 [inline]
>> copy_pud_range root/klinux/mm/memory.c:1270 [inline]
>> copy_p4d_range+0x95e/0xb70 root/klinux/mm/memory.c:1314
>> copy_page_range+0x432/0xa30 root/klinux/mm/memory.c:1408
>> dup_mmap+0x1127/0x1ef0 root/klinux/kernel/fork.c:773
>> dup_mm+0x93/0x4e0 root/klinux/kernel/fork.c:1722
>> copy_mm root/klinux/kernel/fork.c:1781 [inline]
>> copy_process+0x2c89/0x57d0 root/klinux/kernel/fork.c:2436
>> kernel_clone+0xdd/0x910 root/klinux/kernel/fork.c:2849
>> __do_sys_clone+0xcf/0x120 root/klinux/kernel/fork.c:2992
>> do_syscall_x64 root/klinux/arch/x86/entry/common.c:51 [inline]
>> do_syscall_64+0x74/0x360 root/klinux/arch/x86/entry/common.c:81
>> entry_SYSCALL_64_after_hwframe+0x76/0xe0
>> RIP: 0033:0x45d778
>> RSP: 002b:00007ffc4d846860 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
>> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045d778
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
>> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000013782980
>> R10: 0000000013782c50 R11: 0000000000000246 R12: 0000000000000000
>> R13: 0000000000000032 R14: 0000000000000000 R15: 0000000000000000
>>
>> INFO: task syz-executor.10:56553 blocked for more than 143 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:syz-executor.10 state:D stack:0 pid:56553 tgid:56553 ppid:1 flags:0x00000004
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> __alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:244 [inline]
>> alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:271 [inline]
>> alloc_thread_stack_node root/klinux/kernel/fork.c:367 [inline]
>> dup_task_struct+0xa4/0x6c0 root/klinux/kernel/fork.c:1161
>> copy_process+0x4eb/0x57d0 root/klinux/kernel/fork.c:2261
>> kernel_clone+0xdd/0x910 root/klinux/kernel/fork.c:2849
>> __do_sys_clone+0xcf/0x120 root/klinux/kernel/fork.c:2992
>> do_syscall_x64 root/klinux/arch/x86/entry/common.c:51 [inline]
>> do_syscall_64+0x74/0x360 root/klinux/arch/x86/entry/common.c:81
>> entry_SYSCALL_64_after_hwframe+0x76/0xe0
>> RIP: 0033:0x45d778
>> RSP: 002b:00007ffc6a4dad70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
>> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045d778
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
>> RBP: 0000000000000000 R08: 0000000000000000 R09: 000000002d906980
>> R10: 000000002d906c50 R11: 0000000000000246 R12: 0000000000000000
>> R13: 0000000000000032 R14: 0000000000000001 R15: 0000000000000000
>>
>> INFO: task kworker/12:13:56977 blocked for more than 144 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:kworker/12:13 state:D stack:0 pid:56977 tgid:56977 ppid:2 flags:0x00004000
>> Workqueue: events drain_vmap_area_work
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_timeout+0x268/0x2b0 root/klinux/kernel/time/timer.c:2142
>> do_wait_for_common root/klinux/kernel/sched/completion.c:95 [inline]
>> __wait_for_common+0x3ea/0x600 root/klinux/kernel/sched/completion.c:116
>> __flush_work+0xf4/0x180 root/klinux/kernel/workqueue.c:4125
>> __purge_vmap_area_lazy+0x8e5/0xcf0 root/klinux/mm/vmalloc.c:2324
>> drain_vmap_area_work+0x2c/0x40 root/klinux/mm/vmalloc.c:2349
>> process_one_work+0x90d/0x1aa0 root/klinux/kernel/workqueue.c:3235
>> process_scheduled_works root/klinux/kernel/workqueue.c:3315 [inline]
>> worker_thread+0x633/0xe80 root/klinux/kernel/workqueue.c:3396
>> kthread+0x317/0x420 root/klinux/kernel/kthread.c:388
>> ret_from_fork+0x4ae/0x5e0 root/klinux/arch/x86/kernel/process.c:152
>> ret_from_fork_asm+0x1a/0x30 root/klinux/arch/x86/entry/entry_64.S:293
>>
>> INFO: task kdamond.0:66163 blocked for more than 144 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:kdamond.0 state:D stack:0 pid:66163 tgid:66163 ppid:2 flags:0x00004000
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> alloc_pages_mpol_noprof+0x1ee/0x530 root/klinux/mm/mempolicy.c:2270
>> alloc_slab_page root/klinux/mm/slub.c:2315 [inline]
>> allocate_slab+0x27a/0x3f0 root/klinux/mm/slub.c:2485
>> ___slab_alloc+0x889/0x1060 root/klinux/mm/slub.c:3727
>> __slab_alloc.constprop.0+0x52/0xa0 root/klinux/mm/slub.c:3817
>> __slab_alloc_node root/klinux/mm/slub.c:3870 [inline]
>> slab_alloc_node root/klinux/mm/slub.c:4031 [inline]
>> kmem_cache_alloc_noprof+0x385/0x3e0 root/klinux/mm/slub.c:4050
>> damon_new_region+0x29/0x1a0 root/klinux/mm/damon/core.c:124
>> damon_va_evenly_split_region+0x1f8/0x2c0 root/klinux/mm/damon/vaddr.c:85
>> __damon_va_init_regions root/klinux/mm/damon/vaddr.c:271 [inline]
>> damon_va_init+0x2b5/0x470 root/klinux/mm/damon/vaddr.c:283
>> kdamond_fn+0x289/0x1240 root/klinux/mm/damon/core.c:1432
>> kthread+0x317/0x420 root/klinux/kernel/kthread.c:388
>> ret_from_fork+0x4ae/0x5e0 root/klinux/arch/x86/kernel/process.c:152
>> ret_from_fork_asm+0x1a/0x30 root/klinux/arch/x86/entry/entry_64.S:293
>>
>> INFO: task kworker/u80:5:67724 blocked for more than 144 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:kworker/u80:5 state:D stack:0 pid:67724 tgid:67724 ppid:2 flags:0x00004000
>> Workqueue: events_unbound call_usermodehelper_exec_work
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> __alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:244 [inline]
>> alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:271 [inline]
>> alloc_thread_stack_node root/klinux/kernel/fork.c:367 [inline]
>> dup_task_struct+0xa4/0x6c0 root/klinux/kernel/fork.c:1161
>> copy_process+0x4eb/0x57d0 root/klinux/kernel/fork.c:2261
>> kernel_clone+0xdd/0x910 root/klinux/kernel/fork.c:2849
>> user_mode_thread+0xcb/0x110 root/klinux/kernel/fork.c:2927
>> call_usermodehelper_exec_sync root/klinux/kernel/umh.c:133 [inline]
>> call_usermodehelper_exec_work+0x69/0x170 root/klinux/kernel/umh.c:164
>> process_one_work+0x90d/0x1aa0 root/klinux/kernel/workqueue.c:3235
>> process_scheduled_works root/klinux/kernel/workqueue.c:3315 [inline]
>> worker_thread+0x633/0xe80 root/klinux/kernel/workqueue.c:3396
>> kthread+0x317/0x420 root/klinux/kernel/kthread.c:388
>> ret_from_fork+0x4ae/0x5e0 root/klinux/arch/x86/kernel/process.c:152
>> ret_from_fork_asm+0x1a/0x30 root/klinux/arch/x86/entry/entry_64.S:293
>>
>> INFO: task kworker/u80:9:69412 blocked for more than 144 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:kworker/u80:9 state:D stack:0 pid:69412 tgid:69412 ppid:2 flags:0x00004000
>> Workqueue: events_unbound call_usermodehelper_exec_work
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> __alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:244 [inline]
>> alloc_pages_node_noprof root/klinux/./include/linux/gfp.h:271 [inline]
>> alloc_thread_stack_node root/klinux/kernel/fork.c:367 [inline]
>> dup_task_struct+0xa4/0x6c0 root/klinux/kernel/fork.c:1161
>> copy_process+0x4eb/0x57d0 root/klinux/kernel/fork.c:2261
>> kernel_clone+0xdd/0x910 root/klinux/kernel/fork.c:2849
>> user_mode_thread+0xcb/0x110 root/klinux/kernel/fork.c:2927
>> call_usermodehelper_exec_sync root/klinux/kernel/umh.c:133 [inline]
>> call_usermodehelper_exec_work+0x69/0x170 root/klinux/kernel/umh.c:164
>> process_one_work+0x90d/0x1aa0 root/klinux/kernel/workqueue.c:3235
>> process_scheduled_works root/klinux/kernel/workqueue.c:3315 [inline]
>> worker_thread+0x633/0xe80 root/klinux/kernel/workqueue.c:3396
>> kthread+0x317/0x420 root/klinux/kernel/kthread.c:388
>> ret_from_fork+0x4ae/0x5e0 root/klinux/arch/x86/kernel/process.c:152
>> ret_from_fork_asm+0x1a/0x30 root/klinux/arch/x86/entry/entry_64.S:293
>>
>> INFO: task syz-executor.18:73039 blocked for more than 144 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:syz-executor.18 state:D stack:0 pid:73039 tgid:73039 ppid:1 flags:0x00004004
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> alloc_pages_mpol_noprof+0x1ee/0x530 root/klinux/mm/mempolicy.c:2270
>> folio_alloc_mpol_noprof+0x3b/0xd0 root/klinux/mm/mempolicy.c:2288
>> vma_alloc_folio_noprof+0xaf/0x140 root/klinux/mm/mempolicy.c:2316
>> folio_prealloc root/klinux/mm/memory.c:1062 [inline]
>> wp_page_copy+0x21a/0x11c0 root/klinux/mm/memory.c:3308
>> do_wp_page+0x762/0x14e0 root/klinux/mm/memory.c:3700
>> handle_pte_fault+0x573/0x730 root/klinux/mm/memory.c:5717
>> __handle_mm_fault+0xae4/0x10d0 root/klinux/mm/memory.c:5844
>> handle_mm_fault+0x376/0x650 root/klinux/mm/memory.c:6009
>> do_user_addr_fault+0x2be/0xc40 root/klinux/arch/x86/mm/fault.c:1330
>> handle_page_fault root/klinux/arch/x86/mm/fault.c:1471 [inline]
>> exc_page_fault+0x5c/0xe0 root/klinux/arch/x86/mm/fault.c:1527
>> asm_exc_page_fault+0x26/0x30 root/klinux/./arch/x86/include/asm/idtentry.h:608
>> RIP: 0033:0x45d8e1
>> RSP: 002b:00007ffd015d5e10 EFLAGS: 00010246
>> RAX: 000000000000003b RBX: 0000000000000000 RCX: 000000000045d778
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
>> RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000701d980
>> R10: 000000000701dc50 R11: 0000000000000246 R12: 000000000000003b
>> R13: 0000000000000032 R14: 0000000000000000 R15: 0000000000000000
>>
>> INFO: task syz-executor.13:74790 blocked for more than 144 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:syz-executor.13 state:D stack:0 pid:74790 tgid:74790 ppid:1 flags:0x00000004
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> alloc_pages_mpol_noprof+0x1ee/0x530 root/klinux/mm/mempolicy.c:2270
>> folio_alloc_mpol_noprof+0x3b/0xd0 root/klinux/mm/mempolicy.c:2288
>> vma_alloc_folio_noprof+0xaf/0x140 root/klinux/mm/mempolicy.c:2316
>> folio_prealloc root/klinux/mm/memory.c:1062 [inline]
>> wp_page_copy+0x21a/0x11c0 root/klinux/mm/memory.c:3308
>> do_wp_page+0x762/0x14e0 root/klinux/mm/memory.c:3700
>> handle_pte_fault+0x573/0x730 root/klinux/mm/memory.c:5717
>> __handle_mm_fault+0xae4/0x10d0 root/klinux/mm/memory.c:5844
>> handle_mm_fault+0x376/0x650 root/klinux/mm/memory.c:6009
>> do_user_addr_fault+0x2be/0xc40 root/klinux/arch/x86/mm/fault.c:1330
>> handle_page_fault root/klinux/arch/x86/mm/fault.c:1471 [inline]
>> exc_page_fault+0x5c/0xe0 root/klinux/arch/x86/mm/fault.c:1527
>> asm_exc_page_fault+0x26/0x30 root/klinux/./arch/x86/include/asm/idtentry.h:608
>> RIP: 0033:0x45d8e1
>> RSP: 002b:00007ffe18ac7000 EFLAGS: 00010246
>> RAX: 0000000000000038 RBX: 0000000000000000 RCX: 000000000045d778
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
>> RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000eb5f980
>> R10: 000000000eb5fc50 R11: 0000000000000246 R12: 0000000000000038
>> R13: 0000000000000032 R14: 0000000000000001 R15: 0000000000000000
>>
>> INFO: task syz-executor.5:78550 blocked for more than 144 seconds.
>> Tainted: G S ------- ---- 6.6.89+ #931
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> task:syz-executor.5 state:D stack:0 pid:78550 tgid:78550 ppid:1 flags:0x00000004
>> Call Trace:
>>
>> context_switch root/klinux/kernel/sched/core.c:5346 [inline]
>> __schedule+0x7bc/0x1310 root/klinux/kernel/sched/core.c:6720
>> __schedule_loop root/klinux/kernel/sched/core.c:6797 [inline]
>> schedule+0xe2/0x290 root/klinux/kernel/sched/core.c:6812
>> schedule_preempt_disabled+0x18/0x30 root/klinux/kernel/sched/core.c:6869
>> __mutex_lock_common root/klinux/kernel/locking/mutex.c:679 [inline]
>> __mutex_lock+0x914/0x13a0 root/klinux/kernel/locking/mutex.c:747
>> class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> do_shrink_slab+0x3c9/0xf30 root/klinux/mm/shrinker.c:435
>> shrink_slab+0x175/0x5e0 root/klinux/mm/shrinker.c:662
>> shrink_node_memcgs+0x4d6/0x700 root/klinux/mm/vmscan.c:5900
>> shrink_node+0x247/0x12c0 root/klinux/mm/vmscan.c:5933
>> shrink_zones root/klinux/mm/vmscan.c:6175 [inline]
>> do_try_to_free_pages+0x314/0x1580 root/klinux/mm/vmscan.c:6237
>> try_to_free_pages+0x293/0x740 root/klinux/mm/vmscan.c:6472
>> __perform_reclaim root/klinux/mm/page_alloc.c:3965 [inline]
>> __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> __alloc_pages_slowpath.constprop.0+0x800/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> __alloc_pages_noprof+0x490/0x570 root/klinux/mm/page_alloc.c:4792
>> alloc_pages_mpol_noprof+0x1ee/0x530 root/klinux/mm/mempolicy.c:2270
>> folio_alloc_mpol_noprof+0x3b/0xd0 root/klinux/mm/mempolicy.c:2288
>> vma_alloc_folio_noprof+0xaf/0x140 root/klinux/mm/mempolicy.c:2316
>> folio_prealloc root/klinux/mm/memory.c:1062 [inline]
>> wp_page_copy+0x21a/0x11c0 root/klinux/mm/memory.c:3308
>> do_wp_page+0x762/0x14e0 root/klinux/mm/memory.c:3700
>> handle_pte_fault+0x573/0x730 root/klinux/mm/memory.c:5717
>> __handle_mm_fault+0xae4/0x10d0 root/klinux/mm/memory.c:5844
>> handle_mm_fault+0x376/0x650 root/klinux/mm/memory.c:6009
>> do_user_addr_fault+0x2be/0xc40 root/klinux/arch/x86/mm/fault.c:1330
>> handle_page_fault root/klinux/arch/x86/mm/fault.c:1471 [inline]
>> exc_page_fault+0x5c/0xe0 root/klinux/arch/x86/mm/fault.c:1527
>> asm_exc_page_fault+0x26/0x30 root/klinux/./arch/x86/include/asm/idtentry.h:608
>> RIP: 0033:0x45d8e1
>> RSP: 002b:00007fff9b912230 EFLAGS: 00010246
>> RAX: 0000000000000019 RBX: 0000000000000000 RCX: 000000000045d778
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
>> RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000cd3c980
>> R10: 000000000cd3cc50 R11: 0000000000000246 R12: 0000000000000019
>> R13: 0000000000000032 R14: 0000000000000001 R15: 0000000000000000
>>
>> Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings
>>
>> Showing all locks held in the system:
>> 2 locks held by kthreadd/2:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 4 locks held by kworker/u80:6/141:
>> #0: ffff8881041a4d58 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x803/0x1aa0 root/klinux/kernel/workqueue.c:3210
>> #1: ffff8881053cfd80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x859/0x1aa0 root/klinux/kernel/workqueue.c:3211
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 1 lock held by khungtaskd/155:
>> #0: ffffffff8b33eb00 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire root/klinux/./include/linux/rcupdate.h:334 [inline]
>> #0: ffffffff8b33eb00 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock root/klinux/./include/linux/rcupdate.h:786 [inline]
>> #0: ffffffff8b33eb00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 root/klinux/kernel/locking/lockdep.c:6721
>> 2 locks held by bash/957:
>> #0: ffff88800310d0a8 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x29/0x80 root/klinux/drivers/tty/tty_ldisc.c:243
>> #1: ffffc900039852f8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd55/0x1230 root/klinux/drivers/tty/n_tty.c:2217
>> 5 locks held by syz-executor.0/37820:
>> #0: ffffffff8b511780 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap+0xbe/0x1ef0 root/klinux/kernel/fork.c:668
>> #1: ffff888106b396e8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable root/klinux/./include/linux/mmap_lock.h:124 [inline]
>> #1: ffff888106b396e8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap+0xdc/0x1ef0 root/klinux/kernel/fork.c:669
>> #2: ffff88801ff62be8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: mmap_write_lock_nested root/klinux/./include/linux/mmap_lock.h:115 [inline]
>> #2: ffff88801ff62be8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mmap+0x125/0x1ef0 root/klinux/kernel/fork.c:678
>> #3: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #3: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #3: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #4: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #4: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 2 locks held by bash/41651:
>> #0: ffff88801f8cb8a8 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x29/0x80 root/klinux/drivers/tty/tty_ldisc.c:243
>> #1: ffffc900001fd2f8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd55/0x1230 root/klinux/drivers/tty/n_tty.c:2217
>> 2 locks held by syz-executor.10/56553:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by kworker/12:13/56977:
>> #0: ffff88810419cb58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x803/0x1aa0 root/klinux/kernel/workqueue.c:3210
>> #1: ffff88804264fd80 (drain_vmap_work){+.+.}-{0:0}, at: process_one_work+0x859/0x1aa0 root/klinux/kernel/workqueue.c:3211
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: drain_vmap_area_work+0x1c/0x40 root/klinux/mm/vmalloc.c:2348
>> 2 locks held by kdamond.0/66163:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 4 locks held by kworker/u80:5/67724:
>> #0: ffff8881041a4d58 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x803/0x1aa0 root/klinux/kernel/workqueue.c:3210
>> #1: ffff88804664fd80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x859/0x1aa0 root/klinux/kernel/workqueue.c:3211
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 4 locks held by kworker/u80:9/69412:
>> #0: ffff8881041a4d58 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x803/0x1aa0 root/klinux/kernel/workqueue.c:3210
>> #1: ffff8880346afd80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x859/0x1aa0 root/klinux/kernel/workqueue.c:3211
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.18/73039:
>> #0: ffff888048652940 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff888048652940 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.13/74790:
>> #0: ffff88803e37eeb8 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff88803e37eeb8 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.5/78550:
>> #0: ffff88801f4310e8 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff88801f4310e8 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.26/80991:
>> #0: ffff88801b3c6068 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock root/klinux/./include/linux/mmap_lock.h:146 [inline]
>> #0: ffff88801b3c6068 (&mm->mmap_lock){++++}-{3:3}, at: __mm_populate+0x220/0x360 root/klinux/mm/gup.c:2170
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 4 locks held by syz-executor.5/80992:
>> #0: ffff888104871430 (sb_writers#2){.+.+}-{0:0}, at: get_signal+0x18d9/0x1a60 root/klinux/kernel/signal.c:2915
>> #1: ffff888001a29818 (&sb->s_type->i_mutex_key){++++}-{3:3}, at: inode_lock root/klinux/./include/linux/fs.h:828 [inline]
>> #1: ffff888001a29818 (&sb->s_type->i_mutex_key){++++}-{3:3}, at: generic_file_write_iter+0x91/0x2f0 root/klinux/mm/filemap.c:4181
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 2 locks held by syz-executor.22/81067:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 2 locks held by syz-executor.31/81012:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 2 locks held by syz-executor.31/81059:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.23/81024:
>> #0: ffff88804a3aa080 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff88804a3aa080 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 2 locks held by syz-executor.23/81030:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.27/81031:
>> #0: ffff88802008cb70 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff88802008cb70 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 2 locks held by syz-executor.30/81070:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 4 locks held by syz-executor.28/81036:
>> #0: ffff888104871430 (sb_writers#2){.+.+}-{0:0}, at: filename_create+0xf9/0x4c0 root/klinux/fs/namei.c:3928
>> #1: ffff88817b041270 (&sb->s_type->i_mutex_key/1){+.+.}-{3:3}, at: inode_lock_nested root/klinux/./include/linux/fs.h:863 [inline]
>> #1: ffff88817b041270 (&sb->s_type->i_mutex_key/1){+.+.}-{3:3}, at: filename_create+0x1a1/0x4c0 root/klinux/fs/namei.c:3935
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.12/81086:
>> #0: ffff88801f2a45f8 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff88801f2a45f8 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 4 locks held by syz-executor.22/81082:
>> #0: ffff888104871430 (sb_writers#2){.+.+}-{0:0}, at: get_signal+0x18d9/0x1a60 root/klinux/kernel/signal.c:2915
>> #1: ffff88805c122910 (&sb->s_type->i_mutex_key){++++}-{3:3}, at: inode_lock root/klinux/./include/linux/fs.h:828 [inline]
>> #1: ffff88805c122910 (&sb->s_type->i_mutex_key){++++}-{3:3}, at: generic_file_write_iter+0x91/0x2f0 root/klinux/mm/filemap.c:4181
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #2: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #3: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.17/81084:
>> #0: ffff888084e01430 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff888084e01430 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.21/81088:
>> #0: ffff88801cde23c8 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff88801cde23c8 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.5/81089:
>> #0: ffff888004d1abe8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock root/klinux/./include/linux/mmap_lock.h:165 [inline]
>> #0: ffff888004d1abe8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully root/klinux/mm/memory.c:6036 [inline]
>> #0: ffff888004d1abe8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x35/0x5c0 root/klinux/mm/memory.c:6096
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.13/81090:
>> #0: ffff888004d1f568 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock root/klinux/./include/linux/mmap_lock.h:165 [inline]
>> #0: ffff888004d1f568 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully root/klinux/mm/memory.c:6036 [inline]
>> #0: ffff888004d1f568 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x35/0x5c0 root/klinux/mm/memory.c:6096
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.18/81091:
>> #0: ffff888004d1d5e8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock root/klinux/./include/linux/mmap_lock.h:165 [inline]
>> #0: ffff888004d1d5e8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully root/klinux/mm/memory.c:6036 [inline]
>> #0: ffff888004d1d5e8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x35/0x5c0 root/klinux/mm/memory.c:6096
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 2 locks held by syz-executor.7/81096:
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #0: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #1: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>> 3 locks held by syz-executor.16/81095:
>> #0: ffff88801de15e08 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read root/klinux/./include/linux/mm.h:694 [inline]
>> #0: ffff88801de15e08 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x1c7/0x6f0 root/klinux/mm/memory.c:6165
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim root/klinux/mm/page_alloc.c:3962 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim root/klinux/mm/page_alloc.c:3987 [inline]
>> #1: ffffffff8b56b4c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x74d/0x1fb0 root/klinux/mm/page_alloc.c:4394
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: class_mutex_constructor root/klinux/./include/linux/mutex.h:200 [inline]
>> #2: ffffffff8b567390 (vmap_purge_lock){+.+.}-{3:3}, at: vmap_node_shrink_scan+0x1d/0x90 root/klinux/mm/vmalloc.c:5108
>>
>> =============================================
>>
>>
>>> --
>>> Uladzislau Rezki
>>
>> -- 
>> Thanks,
>> Ye Liu
>>
> Thank you!
> 
> I can trigger below:
> 
> <snip>
> Aug 25 13:56:52 pc638 kernel: Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings
> Aug 25 13:56:52 pc638 kernel:
>                               Showing all locks held in the system:
> Aug 25 13:56:52 pc638 kernel: 1 lock held by khungtaskd/488:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3306840 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x47/0x19b
> Aug 25 13:56:52 pc638 kernel: 3 locks held by kworker/52:1/694:
> Aug 25 13:56:52 pc638 kernel:  #0: ffff8ac4401a4140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x57b/0x600
> Aug 25 13:56:52 pc638 kernel:  #1: ffffce26435ffe30 (drain_vmap_work){+.+.}-{0:0}, at: process_one_work+0x1fc/0x600
> Aug 25 13:56:52 pc638 kernel:  #2: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: drain_vmap_area_work+0x1b/0x40
> Aug 25 13:56:52 pc638 kernel: 1 lock held by in:imklog/3831:
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/2/5009:
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/4/5011:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/5/5012:
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/8/5015:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/30/5037:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/31/5038:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/38/5045:
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/39/5046:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/41/5048:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/49/5056:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/51/5058:
> Aug 25 13:56:52 pc638 kernel:  #0: ffffffffa3406300 (vmap_purge_lock){+.+.}-{4:4}, at: alloc_vmap_area+0x8a8/0xd20
> Aug 25 13:56:52 pc638 kernel: 1 lock held by vmalloc_test/57/5064:
> ...
> <snip>
> 
> I think this is with your patch. But i can check also without.
> One potential issue to inline vnode-drain - is a time. At least
> we need to inject cond_resched() after each vnode flush +
> 
> /*
>  * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list.
>  */
> static void reclaim_and_purge_vmap_areas(void)
> 
> {
> 	mutex_lock(&vmap_purge_lock);
> 	purge_fragmented_blocks_allcpus();
> 	__purge_vmap_area_lazy(ULONG_MAX, 0, true);
> 	mutex_unlock(&vmap_purge_lock);
> }
> 
> here use try-lock as well due to potentially increased flush time.
> 
> Any thoughts?
> 
> --
> Uladzislau Rezki


IIUC we won't have to do inline purge if we switch both places to use mutex_trylock?