INFO: task syz.3.558:7751 blocked for more than 144 seconds.
Not tainted 6.15.0-rc7-next-20250522-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.558 state:D stack:25504 pid:7751 tgid:7748 ppid:5840 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
netfs_wait_for_request+0x1f0/0x600 fs/netfs/misc.c:450
netfs_unbuffered_write_iter_locked+0x52a/0x910 fs/netfs/direct_write.c:110
netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:193
do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1
vfs_writev+0x306/0x9a0 fs/read_write.c:1057
do_writev+0x14d/0x2d0 fs/read_write.c:1103
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb7d9f8e969
RSP: 002b:00007fb7dad49038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fb7da1b5fa0 RCX: 00007fb7d9f8e969
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007fb7da010ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb7da1b5fa0 R15: 00007fff1cd60008
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/0:2/981:
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90003affbc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003affbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#2: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
2 locks held by getty/5597:
#0: ffff8880308040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by syz.3.558/7751:
#0: ffff888075f7d978 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
#1: ffff888079a20428 (sb_writers#15){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline]
#1: ffff888079a20428 (sb_writers#15){.+.+}-{0:0}, at: vfs_writev+0x274/0x9a0 fs/read_write.c:1055
#2: ffff8880589c8e28 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x1ef/0x230 fs/netfs/locking.c:188
1 lock held by syz-executor/8133:
1 lock held by syz.1.701/8296:
1 lock held by sed/9122:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 48 Comm: kworker/u8:3 Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:lockdep_hardirqs_on+0x67/0x150 kernel/locking/lockdep.c:4463
Code: 8b 05 3d 96 38 07 85 c0 75 7b 65 8b 05 ea 92 38 07 85 c0 75 70 83 3d 07 a9 43 0e 00 75 32 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 75 6e 83 3d e9 a8 43 0e 00 75 14 48 8b 83 c8
RSP: 0018:ffffc90000b978b8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888021af1e00 RCX: 976135d8f689f000
RDX: 0000000000000006 RSI: ffffffff8db6a54c RDI: ffffffff818590fd
RBP: ffffc90000b97978 R08: ffffffff8fa124f7 R09: 1ffffffff1f4249e
R10: dffffc0000000000 R11: fffffbfff1f4249f R12: ffffffff8b324438
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000172f1c
FS: 0000000000000000(0000) GS:ffff888125d59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc310770c8 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__local_bh_enable_ip+0x12d/0x1c0 kernel/softirq.c:412
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x318/0x3b0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245