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From: Uladzislau Rezki <urezki@gmail.com>
X-Google-Original-From: Uladzislau Rezki <urezki@milan>
Date: Tue, 25 Aug 2026 19:40:15 +0200
To: Ye Liu <ye.liu@linux.dev>
Cc: Uladzislau Rezki <urezki@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ye Liu <liuye@kylinos.cn>, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/vmalloc: fix vmap_purge_lock livelock under memory
 pressure
Message-ID: <ao3Tf193sQpS22c-@milan>
References: <20260824095020.1225189-1-ye.liu@linux.dev>
 <aoxE7rw6gru13DB5@milan>
 <0c34aab2-9b73-45c0-8fbe-e33895bc8eef@linux.dev>
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In-Reply-To: <0c34aab2-9b73-45c0-8fbe-e33895bc8eef@linux.dev>

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@kylinos.cn>
> >>
> >> 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@kylinos.cn>
> >> ---
> >>  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