Kernel bug: INFO: task hung in mISDN_ioctl
Subsystem: isdn4linux, nilfs
Status: open

Crash report:
INFO: task syz-executor371:5847 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc6-syzkaller-00202-ga29967be967e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor371 state:D stack:22288 pid:5847  tgid:5847  ppid:5844   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 mISDN_ioctl+0x96/0x810 drivers/isdn/mISDN/timerdev.c:226
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f250416fd09
RSP: 002b:00007fff88981fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000400000000040 RCX: 00007f250416fd09
RDX: 0000400000001f00 RSI: 0000000080044940 RDI: 0000000000000005
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000555585b92378
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff88982010 R14: 00007fff88981ffc R15: 00007f25041b801d
 </TASK>
INFO: task syz-executor371:5848 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc6-syzkaller-00202-ga29967be967e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor371 state:D stack:22224 pid:5848  tgid:5848  ppid:5843   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 mISDN_ioctl+0x96/0x810 drivers/isdn/mISDN/timerdev.c:226
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f250416fd09
RSP: 002b:00007fff88981fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000400000000040 RCX: 00007f250416fd09
RDX: 0000400000001f00 RSI: 0000000080044940 RDI: 0000000000000005
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000555585b92378
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff88982010 R14: 00007fff88981ffc R15: 00007f25041b801d
 </TASK>
INFO: task syz-executor371:5851 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc6-syzkaller-00202-ga29967be967e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor371 state:D stack:22368 pid:5851  tgid:5851  ppid:5849   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 mISDN_ioctl+0x96/0x810 drivers/isdn/mISDN/timerdev.c:226
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f250416fd09
RSP: 002b:00007fff88981fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000400000000040 RCX: 00007f250416fd09
RDX: 0000400000001f00 RSI: 0000000080044940 RDI: 0000000000000005
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000555585b92378
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff88982010 R14: 00007fff88981ffc R15: 00007f25041b801d
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by getty/5582:
 #0: ffff8880318030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
3 locks held by syz-executor371/5845:
1 lock held by syz-executor371/5847:
 #0: ffffffff8fbf9fe8 (mISDN_mutex){+.+.}-{4:4}, at: mISDN_ioctl+0x96/0x810 drivers/isdn/mISDN/timerdev.c:226
1 lock held by syz-executor371/5848:
 #0: ffffffff8fbf9fe8 (mISDN_mutex){+.+.}-{4:4}, at: mISDN_ioctl+0x96/0x810 drivers/isdn/mISDN/timerdev.c:226
1 lock held by syz-executor371/5851:
 #0: ffffffff8fbf9fe8 (mISDN_mutex){+.+.}-{4:4}, at: mISDN_ioctl+0x96/0x810 drivers/isdn/mISDN/timerdev.c:226

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00202-ga29967be967e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5845 Comm: syz-executor371 Not tainted 6.14.0-rc6-syzkaller-00202-ga29967be967e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d f4 03 92 0c 48 89 de 5b e9 f3 66 59 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 00 d5 03 00 65 8b 15 80 f5
RSP: 0018:ffffc9000400fa50 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88807f697418 RCX: ffff88806ffd8000
RDX: 0000000000000004 RSI: ffffffff9022d040 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000005 R09: ffffffff8bf84d8b
R10: 0000000000000004 R11: ffff88806ffd8000 R12: dffffc0000000000
R13: 0000400000001fff R14: ffff88807f697408 R15: 0000400000001000
FS:  0000555585b91380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000400000001f00 CR3: 000000003177c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 ma_slots lib/maple_tree.c:775 [inline]
 mtree_range_walk+0x3fe/0x8e0 lib/maple_tree.c:2790
 mas_state_walk lib/maple_tree.c:3609 [inline]
 mt_find+0x3a8/0x920 lib/maple_tree.c:6889
 find_vma+0xf9/0x170 mm/mmap.c:913
 lock_mm_and_find_vma+0x5f/0x2f0 mm/memory.c:6319
 do_user_addr_fault arch/x86/mm/fault.c:1360 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x1bf/0x8b0 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__put_user_4+0x11/0x20 arch/x86/lib/putuser.S:88
Code: 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90
RSP: 0018:ffffc9000400fe68 EFLAGS: 00050206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000400000001f00
RDX: 0000000000000001 RSI: ffffffff8c2ac600 RDI: ffffffff8c802e60
RBP: 0000000000000000 R08: ffffffff903bd077 R09: 1ffffffff2077a0e
R10: dffffc0000000000 R11: fffffbfff2077a0f R12: 0000400000001f00
R13: ffff88801dae7d28 R14: dffffc0000000000 R15: 0000000000000000
 mISDN_ioctl+0x694/0x810 drivers/isdn/mISDN/timerdev.c:241
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f250416fd09
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff88981fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000400000000040 RCX: 00007f250416fd09
RDX: 0000400000001f00 RSI: 0000000080044940 RDI: 0000000000000005
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000555585b92378
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff88982010 R14: 00007fff88981ffc R15: 00007f25041b801d
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.247 msecs