INFO: task kworker/u4:3:890 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:3 state:D stack:25232 pid: 890 ppid: 2 flags:0x00004000
Workqueue: btrfs-endio-write btrfs_work_helper
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
wait_on_state fs/btrfs/extent_io.c:868 [inline]
wait_extent_bit+0x3ad/0x4e0 fs/btrfs/extent_io.c:906
lock_extent_bits+0x85/0x110 fs/btrfs/extent_io.c:1469
btrfs_finish_ordered_io+0x6ab/0x1be0 fs/btrfs/inode.c:3108
btrfs_work_helper+0x354/0xb80 fs/btrfs/async-thread.c:325
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
INFO: task syz.0.15:5075 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.15 state:D stack:24016 pid: 5075 ppid: 4811 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
wait_on_state fs/btrfs/extent_io.c:868 [inline]
wait_extent_bit+0x3ad/0x4e0 fs/btrfs/extent_io.c:906
lock_extent_bits+0x85/0x110 fs/btrfs/extent_io.c:1469
btrfs_page_mkwrite+0x5cf/0xc80 fs/btrfs/inode.c:8976
do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922
wp_page_shared+0x16b/0x6d0 mm/memory.c:3259
handle_pte_fault mm/memory.c:4668 [inline]
__handle_mm_fault mm/memory.c:4785 [inline]
handle_mm_fault+0x1f06/0x4410 mm/memory.c:4883
do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355
handle_page_fault arch/x86/mm/fault.c:1443 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
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: 0000:ffffc90002fff6a0 EFLAGS: 00050202
RAX: ffffffff83e40901 RBX: 0000000000000038 RCX: 0000000000000007
RDX: 0000000000000000 RSI: ffffc90002fff740 RDI: 00000000200003a0
RBP: 0000000000000000 R08: 0000000000000000 R09: 1ffff920005ffeee
R10: dffffc0000000000 R11: fffff520005ffeef R12: 00007ffffffff000
R13: 00000000200003d8 R14: ffffc90002fff740 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+0xf0/0x130 lib/usercopy.c:40
copy_to_user include/linux/uaccess.h:200 [inline]
fiemap_fill_next_extent+0x1ba/0x390 fs/ioctl.c:144
emit_fiemap_extent fs/btrfs/extent_io.c:5468 [inline]
extent_fiemap+0x120d/0x15b0 fs/btrfs/extent_io.c:5694
btrfs_fiemap+0xc0/0x110 fs/btrfs/inode.c:8599
ioctl_fiemap fs/ioctl.c:219 [inline]
do_vfs_ioctl+0x152d/0x1ef0 fs/ioctl.c:814
__do_sys_ioctl fs/ioctl.c:872 [inline]
__se_sys_ioctl+0x83/0x170 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f49643c3f69
RSP: 002b:00007f4963638058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f496458ffa0 RCX: 00007f49643c3f69
RDX: 0000000020000380 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 00007f4964447b87 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f496458ffa0 R15: 00007ffd2886cd28
Showing all locks held in the system:
1 lock held by ksoftirqd/1/20:
#0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
1 lock held by khungtaskd/27:
#0: ffffffff8c31f320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/890:
#0: ffff88807dcb1938 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc900046afd00 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
1 lock held by syslogd/3543:
#0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
1 lock held by klogd/3550:
#0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by getty/3945:
#0: ffff88802cea0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:6/4251:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000301fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#2: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
3 locks held by syz.0.15/5075:
#0: ffff88805dfedc28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88805dfedc28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffff888078ce4558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922
#2: ffff888061578e68 (&ei->i_mmap_lock){.+.+}-{3:3}, at: btrfs_page_mkwrite+0x480/0xc80 fs/btrfs/inode.c:8965
1 lock held by udevd/5099:
#0: ffff88802077bd18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by syz.1.576/6243:
#0: ffff88802077bd18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff888020b75468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4353 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:__mutex_lock_common+0x117/0x2400 kernel/locking/mutex.c:575
Code: 3d 0d 91 68 0c 00 75 30 48 8b 04 24 48 8d 78 60 48 89 f8 48 c1 e8 03 80 3c 18 00 74 05 e8 51 16 f9 f7 48 8b 04 24 48 39 40 60 <48> 8d bc 24 e0 00 00 00 0f 85 dc 17 00 00 ba 28 00 00 00 31 f6 e8
RSP: 0018:ffffc9000327f7a0 EFLAGS: 00000246
RAX: ffff888074d88cd8 RBX: dffffc0000000000 RCX: ffffffff962dcf03
RDX: ffff88807b329dc0 RSI: ffffffff8a2b43a0 RDI: ffff888074d88d38
RBP: ffffc9000327f940 R08: ffffffff89461b50 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000000
R13: 1ffff9200064ff0c R14: ffffffff89461b50 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3df7506000 CR3: 000000007512c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
sdata_lock net/mac80211/ieee80211_i.h:1036 [inline]
ieee80211_ibss_rx_queued_mgmt+0x100/0x2ab0 net/mac80211/ibss.c:1632
ieee80211_iface_process_skb net/mac80211/iface.c:1459 [inline]
ieee80211_iface_work+0x70e/0xc60 net/mac80211/iface.c:1513
cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:433
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287