INFO: task syz-executor380:5905 blocked for more than 143 seconds. Not tainted 6.6.94-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor380 state:D stack:24232 pid:5905 ppid:5792 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14e2/0x4580 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 perf_pending_task_sync kernel/events/core.c:5215 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5221 put_event kernel/events/core.c:5349 [inline] perf_event_release_kernel+0x836/0x8c0 kernel/events/core.c:5474 perf_release+0x3b/0x40 kernel/events/core.c:5484 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x903/0x23c0 kernel/exit.c:874 do_group_exit+0x21b/0x2d0 kernel/exit.c:1023 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4877433ab9 RSP: 002b:00007ffe12566a68 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff2 RBX: 0000000000000000 RCX: 00007f4877433ab9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe12566a7c R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5538: #0: ffff888031c520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5130 Comm: klogd Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:find_next_and_bit include/linux/find.h:93 [inline] RIP: 0010:select_idle_smt kernel/sched/fair.c:7350 [inline] RIP: 0010:select_idle_sibling kernel/sched/fair.c:7644 [inline] RIP: 0010:select_task_rq_fair+0x1eb4/0x3220 kernel/sched/fair.c:8235 Code: c0 88 18 02 00 49 01 c6 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 f7 e8 1f 87 7e 00 4d 8b 36 <48> 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 RSP: 0018:ffffc900032777b8 EFLAGS: 00000046 RAX: 1ffff110171c4311 RBX: ffff88807cdb4018 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88807cdb4028 R08: dffffc0000000000 R09: 1ffffffff21b0aa4 R10: dffffc0000000000 R11: fffffbfff21b0aa5 R12: 0000000000000000 R13: ffffffff8c7bda30 R14: 0000000000000003 R15: ffffffff8c7bda30 FS: 00007f9c5c395c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b5e8e75660 CR3: 000000002fea0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: select_task_rq kernel/sched/core.c:3634 [inline] try_to_wake_up+0x618/0x10b0 kernel/sched/core.c:4334 autoremove_wake_function+0x17/0x100 kernel/sched/wait.c:424 __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:107 __wake_up_common_lock kernel/sched/wait.c:138 [inline] __wake_up_sync_key+0x111/0x190 kernel/sched/wait.c:213 sock_def_readable+0x1e1/0x430 net/core/sock.c:3329 unix_dgram_sendmsg+0x10cc/0x1720 net/unix/af_unix.c:2089 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9c5c4e5407 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:00007ffc63e8fbc0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f9c5c395c80 RCX: 00007f9c5c4e5407 RDX: 000000000000003d RSI: 00007ffc63e8fd00 RDI: 0000000000000003 RBP: 00007ffc63e90130 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffc63e90148 R13: 00007ffc63e8fd00 R14: 0000000000000022 R15: 00007ffc63e8fd00