syzbot

INFO: task syz.0.16:6018 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16        state:D stack:25096 pid:6018  tgid:6018  ppid:5970   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5351 [inline]
 __schedule+0x1737/0x4d30 kernel/sched/core.c:6954
 __schedule_loop kernel/sched/core.c:7036 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7051
 request_wait_answer fs/fuse/dev.c:566 [inline]
 __fuse_request_send fs/fuse/dev.c:580 [inline]
 __fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:674
 fuse_simple_request fs/fuse/fuse_i.h:1230 [inline]
 fuse_flush+0x5d4/0x800 fs/fuse/file.c:475
 filp_flush+0xbd/0x190 fs/open.c:1547
 filp_close+0x1d/0x40 fs/open.c:1560
 __range_close fs/file.c:767 [inline]
 __do_sys_close_range fs/file.c:826 [inline]
 __se_sys_close_range+0x359/0x650 fs/file.c:790
 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: 0033:0x7fd69b78e9a9
RSP: 002b:00007ffecf19f328 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00000000000278b9 RCX: 00007fd69b78e9a9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fd69b9b7ba0 R08: 0000000000000001 R09: 0000000bcf19f61f
R10: 00007fd69b600000 R11: 0000000000000246 R12: 00007fd69b9b5fac
R13: 00007fd69b9b5fa0 R14: ffffffffffffffff R15: 00007ffecf19f440
 </TASK>
INFO: task syz.1.17:6043 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.17        state:D stack:25096 pid:6043  tgid:6043  ppid:6023   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5351 [inline]
 __schedule+0x1737/0x4d30 kernel/sched/core.c:6954
 __schedule_loop kernel/sched/core.c:7036 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7051
 request_wait_answer fs/fuse/dev.c:566 [inline]
 __fuse_request_send fs/fuse/dev.c:580 [inline]
 __fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:674
 fuse_simple_request fs/fuse/fuse_i.h:1230 [inline]
 fuse_flush+0x5d4/0x800 fs/fuse/file.c:475
 filp_flush+0xbd/0x190 fs/open.c:1547
 filp_close+0x1d/0x40 fs/open.c:1560
 __range_close fs/file.c:767 [inline]
 __do_sys_close_range fs/file.c:826 [inline]
 __se_sys_close_range+0x359/0x650 fs/file.c:790
 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: 0033:0x7f125018e9a9
RSP: 002b:00007ffc5ec9d3c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 000000000002b956 RCX: 00007f125018e9a9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f12503b7ba0 R08: 0000000000000001 R09: 0000000b5ec9d6bf
R10: 00007f1250000000 R11: 0000000000000246 R12: 00007f12503b5fac
R13: 00007f12503b5fa0 R14: ffffffffffffffff R15: 00007ffc5ec9d4e0
 </TASK>

Showing all locks held in the system:
7 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/31:
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5608:
 #0: ffff88814db360a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline]
RIP: 0010:__local_bh_enable_ip+0xbe/0x1c0 kernel/softirq.c:389
Code: 05 37 6a 62 11 85 c0 75 0f 65 8b 05 f4 66 62 11 85 c0 0f 84 d3 00 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 8b 44 24 20 <fa> a9 00 02 00 00 74 0b 49 89 fc e8 b2 80 42 00 4c 89 e7 65 8b 05
RSP: 0018:ffffc900001178e0 EFLAGS: 00000202
RAX: 0000000000000202 RBX: 0000000000000201 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff8b4d7a98
RBP: ffffc90000117978 R08: ffff888077d502c3 R09: 1ffff1100efaa058
R10: dffffc0000000000 R11: ffffed100efaa059 R12: ffff888033427058
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000022f1c
FS:  0000000000000000(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561795d45170 CR3: 000000000e338000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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+0x369/0x610 net/batman-adv/network-coding.c:722
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>