INFO: task syz.0.1630:11823 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1630      state:D stack:27632 pid:11823 tgid:11822 ppid:5616   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
 nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1372
 deactivate_locked_super+0xbe/0x110 fs/super.c:586
 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd40699e159
RSP: 002b:00007fd4078f2028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffe RBX: 00007fd406c25fa0 RCX: 00007fd40699e159
RDX: 0000200000000080 RSI: 0000200000000040 RDI: 0000000000000000
RBP: 00007fd406a3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd406c26038 R14: 00007fd406c25fa0 R15: 00007ffe520617a8
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:12/3357: 3, on CPU#1:
 #0: ffff88801cfaa940 ((wq_completion)cfg80211){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801cfaa940 ((wq_completion)cfg80211){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801cfaa940 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801cfaa940 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000efb7c40 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000efb7c40 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000efb7c40 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000efb7c40 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_dfs_channels_update_work+0xde/0x630 net/wireless/mlme.c:1091
locks held by udevd/4981: 1, last CPU#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by dhcpcd/5276: 1, on CPU#0:
 #0: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #0: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
locks held by getty/5368: 2, on CPU#0:
 #0: ffff8880323540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5620: 4, last CPU#1:
 #0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
 #0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10a/0x480 kernel/fork.c:1595
 #1: ffff8880795bd900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #1: ffff8880795bd900 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716
 #2: ffff88807f923440 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
 #2: ffff88807f923440 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by kworker/u8:15/6027: 3, last CPU#1:
 #0: ffff8880206df140 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880206df140 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880206df140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff8880206df140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90005437c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90005437c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90005437c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90005437c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: blk_mq_run_hw_queue+0x23b/0x4f0 block/blk-mq.c:2355
locks held by kworker/u8:25/6204: 3, on CPU#0:
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801b0a4140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90005f87c40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90005f87c40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90005f87c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90005f87c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
locks held by kworker/u8:26/6205: 6, on CPU#0:
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90005f27c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90005f27c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90005f27c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90005f27c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff90246448 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
 #3: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1714
 #4: ffff888064980800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6906 [inline]
 #4: ffff888064980800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x121/0x200 net/mac80211/iface.c:860
 #5: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #5: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:966
locks held by syz.6.1560/11644: 3, on CPU#1:
 #0: ffff88802a5302b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
 #1: ffff88802c2ce460 (sb_writers#35){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff88802c2ce460 (sb_writers#35){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #2: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:867
locks held by syz.0.1630/11823: 2, on CPU#0:
 #0: ffff88805952c0e8 (&type->s_umount_key#107){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff88805952c0e8 (&type->s_umount_key#107){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
 #0: ffff88805952c0e8 (&type->s_umount_key#107){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
 #1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/13618: 2, on CPU#1:
 #0: ffffffff907c3fa8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff907c3fa8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff907c3fa8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
locks held by syz.3.2260/13872: 7, last CPU#0:
 #0: ffff88802a330460 (sb_writers#37){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff88805d1e17a0 (&type->i_mutex_dir_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff88805d1e17a0 (&type->i_mutex_dir_key#24){+.+.}-{4:4}, at: lookup_open+0x242/0x1a40 fs/namei.c:4458
 #2: ffff88805d1e79a0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #2: ffff88805d1e79a0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x170/0x4850 fs/ocfs2/suballoc.c:904
 #3: ffff88805d3089a0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #3: ffff88805d3089a0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x170/0x4850 fs/ocfs2/suballoc.c:904
 #4: ffff88805d30a5a0 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #4: ffff88805d30a5a0 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x170/0x4850 fs/ocfs2/suballoc.c:904
 #5: ffff88802a330650 (sb_internal#4){.+.+}-{0:0}, at: ocfs2_mknod+0xeed/0x21a0 fs/ocfs2/namei.c:365
 #6: ffff88807684ace0 (&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x3ae/0x700 fs/ocfs2/journal.c:369
locks held by syz.8.2256/13894: 2, last CPU#0:
 #0: ffff88807ec06460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline]
 #0: ffff88807ec06460 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x3764/0x4520 fs/coredump.c:1195
 #1: ffff888050eeef18 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff888050eeef18 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3433
locks held by syz.7.2269/13902: 11, last CPU#1:
 #0: ffff88807f588ef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
 #1: ffff88802560c460 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff88802560c460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #2: ffff8880693cbc80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
 #3: ffff88802b7bd698 (kn->active#79){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #3: ffff88802b7bd698 (kn->active#79){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337
 #4: ffffffff8fcc30e0 (serio_mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline]
 #4: ffffffff8fcc30e0 (serio_mutex){+.+.}-{4:4}, at: drvctl_store+0x35/0x11e0 drivers/input/serio/serio.c:360
 #5: ffff88802b7f3320 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #5: ffff88802b7f3320 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
 #5: ffff88802b7f3320 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
 #6: ffff88802b7f31d0 (&serio->drv_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #6: ffff88802b7f31d0 (&serio->drv_mutex){+.+.}-{4:4}, at: serio_disconnect_driver drivers/input/serio/serio.c:59 [inline]
 #6: ffff88802b7f31d0 (&serio->drv_mutex){+.+.}-{4:4}, at: serio_driver_remove+0x2e/0xa0 drivers/input/serio/serio.c:755
 #7: ffffffff8fcd2f80 (psmouse_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #7: ffffffff8fcd2f80 (psmouse_mutex){+.+.}-{4:4}, at: psmouse_disconnect+0x63/0x8a0 drivers/input/mouse/psmouse-base.c:1461
 #8: ffffffff8fcc8aa0 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #8: ffffffff8fcc8aa0 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x2d8/0x650 drivers/input/input.c:2257
 #9: ffffffff905ff080 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
 #9: ffffffff905ff080 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast+0x27e/0x560 lib/kobject_uevent.c:410
 #10: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #10: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #10: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0xae/0x550 net/core/sock.c:3665
locks held by syz.2.2271/13906: 1, last CPU#1:
 #0: ffff88804d5200a0 (&ctx->uring_lock){+.+.}-{4:4}, at: __do_sys_io_uring_enter io_uring/io_uring.c:2636 [inline]
 #0: ffff88804d5200a0 (&ctx->uring_lock){+.+.}-{4:4}, at: __se_sys_io_uring_enter+0x350/0x1bb0 io_uring/io_uring.c:2586
locks held by syz.8.2272/13912: 8, last CPU#0:
 #0: ffff88807ec06460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline]
 #0: ffff88807ec06460 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x3764/0x4520 fs/coredump.c:1195
 #1: ffff888078db50f0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff888078db50f0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3433
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: percpu_ref_tryget_many include/linux/percpu-refcount.h:241 [inline]
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: percpu_ref_tryget+0x15/0x180 include/linux/percpu-refcount.h:266
 #4: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #4: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #4: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: get_non_dying_memcg_start mm/memcontrol.c:862 [inline]
 #4: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: mod_memcg_lruvec_state+0xd5/0x270 mm/memcontrol.c:992
 #5: ffff8880595372b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline]
 #5: ffff8880595372b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
 #6: ffff88807fbd6978 (key){....}-{2:2}, at: percpu_counter_add_batch+0x116/0x1d0 lib/percpu_counter.c:101
 #7: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #7: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #7: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: get_non_dying_memcg_start mm/memcontrol.c:862 [inline]
 #7: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: mod_memcg_lruvec_state+0xd5/0x270 mm/memcontrol.c:992

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13912 Comm: syz.8.2272 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
RIP: 0010:in_gate_area_no_mm+0x3d/0x60 arch/x86/entry/vsyscall/vsyscall_64.c:352
Code: 0d bf 02 00 00 00 89 ee e8 20 8d 94 00 83 fd 02 40 0f 95 c5 48 81 e3 00 f0 ff ff 48 c7 c7 00 00 60 ff 48 89 de e8 c3 8d 94 00 <48> 81 fb 00 00 60 ff 0f 94 c0 40 20 e8 0f b6 c0 5b 5d e9 c7 dd dc
RSP: 0018:ffffc90000007620 EFLAGS: 00000246
RAX: ffffffff8133632d RBX: 00007f95b439e000 RCX: ffff888021758000
RDX: 8000000000000100 RSI: 00007f95b439e000 RDI: ffffffffff600000
RBP: 0000000000000001 R08: 0000000000000100 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff81b2a320 R12: ffff888021758000
R13: 00000000000000f0 R14: dffffc0000000000 R15: 1ffff92000000eda
FS:  00007f95b53096c0(0000) GS:ffff888124cc8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000002c0 CR3: 000000008a12a000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 is_kernel_text include/linux/kallsyms.h:31 [inline]
 core_kernel_text kernel/extable.c:68 [inline]
 kernel_text_address+0x2d/0xe0 kernel/extable.c:99
 __kernel_text_address+0xd/0x30 kernel/extable.c:79
 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:351 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:377
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 kmem_cache_alloc_node_noprof+0x354/0x610 mm/slub.c:5068
 __alloc_skb+0x1db/0x7a0 net/core/skbuff.c:704
 alloc_skb include/linux/skbuff.h:1384 [inline]
 ndisc_alloc_skb+0xa0/0x480 net/ipv6/ndisc.c:421
 ndisc_send_rs+0x288/0x6b0 net/ipv6/ndisc.c:708
 addrconf_rs_timer+0x2d2/0x6c0 net/ipv6/addrconf.c:4073
 call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:copy_mc_enhanced_fast_string+0x6/0xf arch/x86/lib/copy_mc_64.S:130
Code: 89 ca e9 9d fd ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 89 f8 48 89 d1 <f3> a4 31 c0 e9 4c 00 2b f5 48 89 c8 e9 44 00 2b f5 cc cc cc cc cc
RSP: 0018:ffffc9000486ecb8 EFLAGS: 00000246
RAX: ffff888041b88000 RBX: ffffea0000000000 RCX: 0000000000000fc0
RDX: 0000000000001000 RSI: ffff888067dd6040 RDI: ffff888041b88040
RBP: ffffc9000486eeb0 R08: ffff888067dd6fff R09: 1ffff1100cfbadff
R10: dffffc0000000000 R11: ffffed100cfbae00 R12: dffffc0000000000
R13: ffffc9000486fbe8 R14: ffffea00019f7580 R15: 1ffff9200090ddac
 dump_page_copy fs/coredump.c:1316 [inline]
 dump_user_range+0x31a/0x12c0 fs/coredump.c:1367
 elf_core_dump+0x3485/0x3a90 fs/binfmt_elf.c:2106
 coredump_write+0x1290/0x1960 fs/coredump.c:1047
 do_coredump fs/coredump.c:1126 [inline]
 vfs_coredump+0x3764/0x4520 fs/coredump.c:1195
 get_signal+0x1094/0x12c0 kernel/signal.c:3097
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
 irqentry_exit+0x2ba/0x910 kernel/entry/common.c:165
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f95b439e161
Code: 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f95b4625fa0 RCX: 00007f95b439e159
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f95b443506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f95b4626038 R14: 00007f95b4625fa0 R15: 00007fff1c9bdb08
 </TASK>
sd 0:0:1:0: [sda] tag#5109 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
sd 0:0:1:0: [sda] tag#5109 CDB: Write(10) 2a 00 00 0d 41 36 00 00 08 00
sd 0:0:1:0: [sda] tag#5109 scsi host busy 6 failed 0
sd 0:0:1:0: Notifying upper driver of completion (result 0)
sd 0:0:1:0: [sda] tag#5109 sd_done: completed 4096 of 4096 bytes
sd 0:0:1:0: [sda] tag#5109 8 sectors total, 4096 bytes done.
sd 0:0:1:0: [sda] tag#5106 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
sd 0:0:1:0: [sda] tag#5106 CDB: Write(10) 2a 00 00 0d 81 36 00 00 08 00
sd 0:0:1:0: [sda] tag#5106 scsi host busy 5 failed 0
sd 0:0:1:0: Notifying upper driver of completion (result 0)
sd 0:0:1:0: [sda] tag#5106 sd_done: completed 4096 of 4096 bytes
sd 0:0:1:0: [sda] tag#5106 8 sectors total, 4096 bytes done.
sd 0:0:1:0: [sda] tag#5107 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
sd 0:0:1:0: [sda] tag#5107 CDB: Write(10) 2a 00 00 0d a1 2e 00 00 08 00
sd 0:0:1:0: [sda] tag#5107 scsi host busy 4 failed 0
sd 0:0:1:0: Notifying upper driver of completion (result 0)
sd 0:0:1:0: [sda] tag#5107 sd_done: completed 4096 of 4096 bytes
sd 0:0:1:0: [sda] tag#5107 8 sectors total, 4096 bytes done.
sd 0:0:1:0: [sda] tag#5105 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
sd 0:0:1:0: [sda] tag#5105 CDB: Write(10) 2a 00 00 0d 70 66 00 00 d0 00
sd 0:0:1:0: [sda] tag#5105 scsi host busy 3 failed 0
sd 0:0:1:0: Notifying upper driver of completion (result 0)
sd 0:0:1:0: [sda] tag#5105 sd_done: completed 106496 of 106496 bytes
sd 0:0:1:0: [sda] tag#5105 208 sectors total, 106496 bytes done.
sd 0:0:1:0: [sda] tag#5110 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
sd 0:0:1:0: [sda] tag#5110 CDB: Write(10) 2a 00 00 0d 61 2e 00 00 08 00
sd 0:0:1:0: [sda] tag#5110 scsi host busy 2 failed 0
sd 0:0:1:0: Notifying upper driver of completion (result 0)
sd 0:0:1:0: [sda] tag#5110 sd_done: completed 4096 of 4096 bytes
sd 0:0:1:0: [sda] tag#5110 8 sectors total, 4096 bytes done.
sd 0:0:1:0: [sda] tag#5108 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
sd 0:0:1:0: [sda] tag#5108 CDB: Write(10) 2a 00 00 0d b0 76 00 00 c0 00
sd 0:0:1:0: [sda] tag#5108 scsi host busy 1 failed 0
sd 0:0:1:0: Notifying upper driver of completion (result 0)
sd 0:0:1:0: [sda] tag#5108 sd_done: completed 98304 of 98304 bytes
sd 0:0:1:0: [sda] tag#5108 192 sectors total, 98304 bytes done.