INFO: task syz.0.424:8039 blocked for more than 143 seconds.
Not tainted 6.16.0-rc4-next-20250704-syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.424 state:D stack:24968 pid:8039 tgid:8037 ppid:7099 task_flags:0x40044c flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5318 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6701
__schedule_loop kernel/sched/core.c:6779 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6794
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
exit_aio+0x2f1/0x3b0 fs/aio.c:927
__mmput+0x68/0x420 kernel/fork.c:1117
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b4098e929
RSP: 002b:00007f7b3e7f60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7b40bb6088 RCX: 00007f7b4098e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7b40bb6088
RBP: 00007f7b40bb6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7b40bb608c
R13: 0000000000000000 R14: 00007ffde1874730 R15: 00007ffde1874818
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13bf60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13bf60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13bf60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
5 locks held by kworker/u8:5/1052:
2 locks held by getty/5609:
#0: ffff888032aa00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/u9:5/5861:
#0: ffff888021f73948 ((wq_completion)bcachefs#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff888021f73948 ((wq_completion)bcachefs#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffff8880b8723f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39a/0x6d0 kernel/sched/psi.c:991
#2: ffff88806a79e330 (&wp->writes_lock){..-.}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
#2: ffff88806a79e330 (&wp->writes_lock){..-.}-{3:3}, at: bch2_write_point_do_index_updates+0xad/0x570 fs/bcachefs/io_write.c:708
2 locks held by syz.4.334/7576:
2 locks held by syz-executor/7831:
2 locks held by bch-rebalance/l/8084:
2 locks held by syz.3.806/9756:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-next-20250704-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+0x70e/0x8a0 kernel/kthread.c:463
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8478 Comm: kworker/u8:20 Not tainted 6.16.0-rc4-next-20250704-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_dat_purge
RIP: 0010:check_preemption_disabled+0x25/0x120 lib/smp_processor_id.c:16
Code: 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 ae 56 2b 07 48 89 44 24 08 65 8b 05 b6 56 2b 07 65 8b 0d ab 56 2b 07 c1 ff ff ff 7f 74 23 65 48 8b 0d 8b 56 2b 07 48 3b 4c 24 08 0f
RSP: 0018:ffffc90003dbf910 EFLAGS: 00000082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000202
RDX: 0000000000000000 RSI: ffffffff8be333e0 RDI: ffffffff8be333a0
RBP: ffffc90003dbfa08 R08: ffffffff8fa25d37 R09: 1ffffffff1f44ba6
R10: dffffc0000000000 R11: fffffbfff1f44ba7 R12: ffffffff8b42bd6a
R13: ffff888067480998 R14: dffffc0000000000 R15: 1ffff920007b7f30
FS: 0000000000000000(0000) GS:ffff888125be7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f20daf82178 CR3: 000000002c12c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000004144
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751
trace_irq_disable+0x37/0x110 include/trace/events/preemptirq.h:36
__local_bh_enable_ip+0xce/0x1c0 kernel/softirq.c:389
spin_unlock_bh include/linux/spinlock.h:396 [inline]
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:185 [inline]
batadv_dat_purge+0x2da/0x3c0 net/batman-adv/distributed-arp-table.c:204
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245