INFO: task syz-executor303:5868 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor303 state:D stack:26920 pid:5868  tgid:5868  ppid:5867   task_flags:0x40004c flags:0x00004002
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
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088
 __down_read_common kernel/locking/rwsem.c:1263 [inline]
 __down_read kernel/locking/rwsem.c:1276 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541
 mmap_read_lock include/linux/mmap_lock.h:412 [inline]
 exit_mm+0xcc/0x2c0 kernel/exit.c:557
 do_exit+0x648/0x2300 kernel/exit.c:947
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
 __do_sys_exit_group kernel/exit.c:1111 [inline]
 __se_sys_exit_group kernel/exit.c:1109 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1109
 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
 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: 0033:0x7fa39a6af309
RSP: 002b:00007ffea1c87798 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa39a6af309
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007fa39a73b2b0 R08: ffffffffffffffb0 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa39a73b2b0
R13: 0000000000000000 R14: 00007fa39a73be40 R15: 00007fa39a67d120
 </TASK>

Showing all locks held in the system:
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/5609:
 #0: ffff8880332fe0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000362c2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor303/5868:
 #0: ffff88807e3ded60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline]
 #0: ffff88807e3ded60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557
1 lock held by syz-executor303/5869:

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

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 05/07/2025
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: 5201 Comm: syslogd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__bfs kernel/locking/lockdep.c:1818 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1863 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2799 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3172 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3287 [inline]
RIP: 0010:validate_chain+0xfd7/0x2140 kernel/locking/lockdep.c:3911
Code: 25 ff 0f 00 00 39 05 64 0e 51 12 73 06 89 05 5c 0e 51 12 49 8b 04 24 48 89 de 48 39 e8 0f 84 33 fe ff ff 4c 89 68 30 48 8b 00 <48> 39 e8 75 f4 48 89 de e9 1f fe ff ff 48 c7 c7 50 e6 40 8e 48 89
RSP: 0018:ffffc90003047258 EFLAGS: 00000002
RAX: ffffffff967b9f68 RBX: 0000000000000111 RCX: 0000000000000002
RDX: 0000000000000008 RSI: 0000000000000111 RDI: ffff88804f1d8000
RBP: ffffffff939046f0 R08: ffffc90003047220 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff819e2480 R12: ffffffff9672a7d8
R13: ffffc900030472e0 R14: ffff88804f1d8b90 R15: 0000000000000001
FS:  00007f3f2ad1ec80(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b014f604b0 CR3: 000000004fb3c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
 lock_hrtimer_base kernel/time/hrtimer.c:171 [inline]
 hrtimer_try_to_cancel+0x22b/0x420 kernel/time/hrtimer.c:1362
 update_curr_dl_se+0x1ef/0x980 kernel/sched/deadline.c:1468
 update_curr+0x3fb/0x730 kernel/sched/fair.c:1243
 enqueue_entity+0x5f/0x1120 kernel/sched/fair.c:5253
 enqueue_task_fair+0x25a/0x1470 kernel/sched/fair.c:6876
 enqueue_task+0x72/0x420 kernel/sched/core.c:2084
 activate_task kernel/sched/core.c:2126 [inline]
 ttwu_do_activate+0x1f3/0x870 kernel/sched/core.c:3735
 ttwu_queue kernel/sched/core.c:3998 [inline]
 try_to_wake_up+0x721/0x12b0 kernel/sched/core.c:4322
 autoremove_wake_function+0x17/0x100 kernel/sched/wait.c:403
 __wake_up_common kernel/sched/wait.c:108 [inline]
 __wake_up_common_lock+0x137/0x1f0 kernel/sched/wait.c:125
 __unix_dgram_recvmsg+0x486/0xd60 net/unix/af_unix.c:2626
 sock_recvmsg_nosec net/socket.c:1065 [inline]
 sock_recvmsg+0x229/0x270 net/socket.c:1087
 sock_read_iter+0x231/0x2f0 net/socket.c:1157
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x4d0/0x980 fs/read_write.c:572
 ksys_read+0x145/0x250 fs/read_write.c:715
 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: 0033:0x7f3f2ae6e407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe3f922cb0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f3f2ad1ec80 RCX: 00007f3f2ae6e407
RDX: 00000000000000ff RSI: 00005568a3d29950 RDI: 0000000000000000
RBP: 00005568a3d29910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005568a3d29982
R13: 0000000000000000 R14: 00005568a3d29950 R15: 000055686ce6fd98
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.325 msecs