INFO: task syz.0.15:4990 blocked for more than 143 seconds.
      Not tainted 5.15.178-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.15        state:D stack:22448 pid: 4990 ppid:  4749 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:8963
 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2920
 wp_page_shared+0x179/0x690 mm/memory.c:3257
 handle_pte_fault mm/memory.c:4666 [inline]
 __handle_mm_fault mm/memory.c:4783 [inline]
 handle_mm_fault+0x2a3d/0x5960 mm/memory.c:4881
 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:ffffc900030bf668 EFLAGS: 00050202
RAX: ffffffff8413e601 RBX: 00000000200003d8 RCX: 0000000000000007
RDX: 0000000000000000 RSI: ffffc900030bf720 RDI: 00000000200003a0
RBP: ffffc900030bf7d0 R08: 0000000000000000 R09: fffff52000617eeb
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000038
R13: 00007ffffffff000 R14: ffffc900030bf720 R15: 00000000200003a0
 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:5461 [inline]
 extent_fiemap+0x1218/0x1650 fs/btrfs/extent_io.c:5687
 btrfs_fiemap+0x121/0x160 fs/btrfs/inode.c:8586
 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: 0033:0x7f3532cf4ed9
RSP: 002b:00007f3531f73058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3532ebafa0 RCX: 00007f3532cf4ed9
RDX: 0000000020000380 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 00007f3532d68cc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3532ebafa0 R15: 00007ffd53d00c48
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1fce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/155:
2 locks held by getty/3930:
 #0: ffff88802cf4b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz.0.15/4990:
 #0: ffff88802c1c2b28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88802c1c2b28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1298 [inline]
 #0: ffff88802c1c2b28 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 #0: ffff88802c1c2b28 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x700 arch/x86/mm/fault.c:1501
 #1: ffff88814732a558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x1a9/0x440 mm/memory.c:2920
 #2: ffff88806e9e1838 (&ei->i_mmap_lock){.+.+}-{3:3}, at: btrfs_page_mkwrite+0x4a2/0xd60 fs/btrfs/inode.c:8952
2 locks held by udevd/5017:
1 lock held by syz.1.435/5873:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5873 Comm: syz.1.435 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:debug_smp_processor_id+0xe/0x10 lib/smp_processor_id.c:60
Code: 00 00 00 00 48 c7 c7 40 ff b2 8a e8 2c 01 00 00 65 ff 0d 11 f1 c3 75 5b c3 cc cc cc 48 c7 c7 60 f2 f9 8a 48 c7 c6 a0 f2 f9 8a <eb> 00 41 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00
RSP: 0018:ffffc900062f76a0 EFLAGS: 00000282
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888018f8bb80
RDX: ffff888018f8bb80 RSI: ffffffff8af9f2a0 RDI: ffffffff8af9f260
RBP: 0000000000000000 R08: ffffffff81c3e247 R09: ffffed100ef76994
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffffea00017cbe40 R14: 0000000000000c68 R15: 00fff00000080003
FS:  00007fe0480e86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe040cc7000 CR3: 000000005d15a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
 rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123
 rcu_read_unlock include/linux/rcupdate.h:768 [inline]
 blk_cgroup_congested include/linux/blk-cgroup.h:290 [inline]
 __cgroup_throttle_swaprate+0x2f0/0x540 mm/swapfile.c:3809
 cgroup_throttle_swaprate include/linux/swap.h:728 [inline]
 shmem_add_to_page_cache+0xd2f/0x17c0 mm/shmem.c:727
 shmem_getpage_gfp+0x1aa1/0x3190 mm/shmem.c:1940
 shmem_getpage mm/shmem.c:151 [inline]
 shmem_write_begin+0xce/0x1a0 mm/shmem.c:2474
 generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacd/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 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: 0033:0x7fe048e6898f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fe0480e7e10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fe048e6898f
RDX: 0000000001000000 RSI: 00007fe03fcc8000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005597
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fe0480e7f10 R14: 00007fe0480e7ed0 R15: 00007fe03fcc8000
 </TASK>