INFO: task kworker/u8:11:7871 blocked for more than 144 seconds.
      Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:11   state:D stack:21112 pid:7871  tgid:7871  ppid:2      task_flags:0x4208160 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5367 [inline]
 __schedule+0x1ac3/0x5090 kernel/sched/core.c:6748
 __schedule_loop kernel/sched/core.c:6825 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6840
 afs_cell_purge+0x3e3/0x550 fs/afs/cell.c:893
 afs_net_exit+0x50/0x100 fs/afs/main.c:146
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x814/0xd60 net/core/net_namespace.c:652
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff8880b8739958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:595
 #1: ffff8880b8723b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41f/0x7a0 kernel/sched/psi.c:987
 #2: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #2: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: batadv_nc_purge_paths+0xe8/0x3b0 net/batman-adv/network-coding.c:442
2 locks held by kworker/1:0/24:
1 lock held by khungtaskd/31:
 #0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6761
2 locks held by getty/5585:
 #0: ffff8880357d80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:11/7871:
 #0: ffff88801baf3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801baf3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
 #1: ffffc90002e27c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90002e27c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8feb7610 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:606
1 lock held by syz.7.3319/17974:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17974 Comm: syz.7.3319 Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x86/0x2a0 mm/kasan/generic.c:189
Code: 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 4c 89 cd 48 f7 d5 48 01 dd 41 80 3b 00 <0f> 85 d6 01 00 00 49 ff c3 48 ff c5 75 ee e9 1e 01 00 00 45 89 dc
RSP: 0018:ffffc9000bab66a8 EFLAGS: 00000246
RAX: ffff88813fffc401 RBX: 1ffff11027fff93f RCX: ffffffff821b0420
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88813fffc9f8
RBP: ffffffffffffffff R08: ffff88813fffc9ff R09: 1ffff11027fff93f
R10: dffffc0000000000 R11: ffffed1027fff93f R12: ffff88813fffe110
R13: 0000000000000000 R14: dffffc0000000001 R15: ffffed1027fff940
FS:  00007f3b9477e6c0(0000) GS:ffff88812535a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ace778ab8 CR3: 00000000693dc000 CR4: 00000000003526f0
DR0: 0000000000000007 DR1: 0000000000000005 DR2: 0000000000000008
DR3: 10000000fffffffe DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 get_page_from_freelist+0x3a0/0x37d0 mm/page_alloc.c:3417
 __alloc_frozen_pages_noprof+0x2c5/0x7b0 mm/page_alloc.c:4740
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 folio_alloc_mpol_noprof+0x36/0x70 mm/mempolicy.c:2320
 shmem_alloc_folio mm/shmem.c:1863 [inline]
 shmem_alloc_and_add_folio+0x490/0x1070 mm/shmem.c:1902
 shmem_get_folio_gfp+0x655/0x1800 mm/shmem.c:2545
 shmem_get_folio mm/shmem.c:2651 [inline]
 shmem_write_begin+0x17e/0x3a0 mm/shmem.c:3301
 generic_perform_write+0x329/0xa10 mm/filemap.c:4102
 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3477
 __kernel_write_iter+0x439/0x990 fs/read_write.c:617
 dump_emit_page fs/coredump.c:885 [inline]
 dump_user_range+0x94a/0xf90 fs/coredump.c:959
 elf_core_dump+0x409d/0x4ae0 fs/binfmt_elf.c:2128
 do_coredump+0x22c3/0x3260 fs/coredump.c:759
 get_signal+0x13ed/0x1730 kernel/signal.c:3020
 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 irqentry_exit_to_user_mode+0x7e/0x250 kernel/entry/common.c:231
 exc_general_protection+0x419/0x5d0 arch/x86/kernel/traps.c:791
 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617
RIP: 0033:0x7f3b9398d171
Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:0000200000000510 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f3b93ba5fa0 RCX: 00007f3b9398d169
RDX: 0000200000000540 RSI: 0000200000000510 RDI: 0000000000200400
RBP: 00007f3b93a0e2a0 R08: 00002000000005c0 R09: 00002000000005c0
R10: 0000200000000580 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3b93ba5fa0 R15: 00007ffc1fa72508
 </TASK>