INFO: task syz.3.177:4918 blocked for more than 144 seconds.
      Not tainted 5.15.171-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.177       state:D stack:22416 pid: 4918 ppid:  4176 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 wait_on_state fs/btrfs/extent_io.c:868 [inline]
 wait_extent_bit+0x3f9/0x530 fs/btrfs/extent_io.c:906
 lock_extent_bits+0x10d/0x1e0 fs/btrfs/extent_io.c:1469
 btrfs_page_mkwrite+0x5f2/0xd60 fs/btrfs/inode.c:8961
 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2909
 wp_page_shared+0x179/0x690 mm/memory.c:3246
 handle_pte_fault mm/memory.c:4655 [inline]
 __handle_mm_fault mm/memory.c:4772 [inline]
 handle_mm_fault+0x2a3d/0x5960 mm/memory.c:4870
 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline]
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0010:copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:92
Code: 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76 40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a
RSP: 0018:ffffc90011f8f668 EFLAGS: 00050202
RAX: ffffffff84095a01 RBX: 0000000020000218 RCX: 0000000000000007
RDX: 0000000000000000 RSI: ffffc90011f8f720 RDI: 00000000200001e0
RBP: ffffc90011f8f7d0 R08: 0000000000000000 R09: fffff520023f1eeb
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000038
R13: 00007ffffffff000 R14: ffffc90011f8f720 R15: 00000000200001e0
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 _copy_to_user+0xef/0x130 lib/usercopy.c:40
 copy_to_user include/linux/uaccess.h:200 [inline]
 fiemap_fill_next_extent+0x231/0x410 fs/ioctl.c:144
 emit_fiemap_extent fs/btrfs/extent_io.c:5448 [inline]
 extent_fiemap+0x1185/0x1650 fs/btrfs/extent_io.c:5687
 btrfs_fiemap+0x121/0x160 fs/btrfs/inode.c:8584
 ioctl_fiemap fs/ioctl.c:219 [inline]
 do_vfs_ioctl+0x1934/0x2b70 fs/ioctl.c:814
 __do_sys_ioctl fs/ioctl.c:872 [inline]
 __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe3bfaca719
RSP: 002b:00007fe3bdf42038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe3bfc81f80 RCX: 00007fe3bfaca719
RDX: 00000000200001c0 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 00007fe3bfb3d75e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe3bfc81f80 R15: 00007ffe31e63568
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:2/154:
 #0: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffffc90001fe7d20 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
1 lock held by udevd/3546:
 #0: ffff8880205ba118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
2 locks held by getty/3921:
 #0: ffff88802c321098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cbe2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz.3.177/4918:
 #0: ffff888074703228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888074703228 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1298 [inline]
 #0: ffff888074703228 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 #0: ffff888074703228 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x700 arch/x86/mm/fault.c:1501
 #1: ffff888079858558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x1a9/0x440 mm/memory.c:2909
 #2: ffff8880737f8e68 (&ei->i_mmap_lock){++++}-{3:3}, at: btrfs_page_mkwrite+0x4a2/0xd60 fs/btrfs/inode.c:8950
2 locks held by btrfs-cleaner/4960:
 #0: ffff888079858460 (sb_writers#21){.+.+}-{0:0}, at: cleaner_kthread+0x205/0x390 fs/btrfs/disk-io.c:1829
 #1: ffff8880737f8fe0 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #1: ffff8880737f8fe0 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: btrfs_inode_lock+0x49/0xd0 fs/btrfs/inode.c:124
3 locks held by kworker/0:10/5077:
 #0: ffff888017070938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900046c7d20 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #2: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
2 locks held by kworker/0:13/5080:
 #0: ffff888017072138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900046f7d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
3 locks held by syz.5.664/6891:
2 locks held by syz.1.673/6916:
 #0: ffff8880205ba118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
 #1: ffff888147758468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.171-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4464 Comm: kworker/u4:12 Not tainted 5.15.171-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_release kernel/locking/lockdep.c:5279 [inline]
RIP: 0010:lock_release+0x199/0x9a0 kernel/locking/lockdep.c:5643
Code: 24 b0 00 00 00 fa 48 c7 c7 80 38 8b 8a e8 4f 6f d1 08 65 ff 05 98 94 9f 7e 48 8d 94 24 80 00 00 00 48 c1 ea 03 42 0f b6 04 3a <84> c0 4c 8b 6c 24 18 0f 85 56 05 00 00 c7 84 24 80 00 00 00 01 00
RSP: 0018:ffffc90004f3fa00 EFLAGS: 00000806
RAX: 0000000000000004 RBX: 0000000000000246 RCX: ffffffff8162e388
RDX: 1ffff920009e7f50 RSI: ffffffff8a8b3880 RDI: ffffffff8ad90500
RBP: ffffc90004f3fb38 R08: dffffc0000000000 R09: fffffbfff1bd2cd6
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920009e7f4c
R13: ffffffff8a11a14e R14: ffffc90004f3fab0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff2e75d9ee1 CR3: 0000000025a15000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline]
 _raw_spin_unlock_bh+0x17/0x30 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:408 [inline]
 batadv_nc_purge_paths+0x30e/0x3b0 net/batman-adv/network-coding.c:475
 batadv_nc_worker+0x30b/0x5b0 net/batman-adv/network-coding.c:726
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>