syzbot

INFO: task syz-executor.3:11953 can't die for more than 143 seconds.
task:syz-executor.3  state:R  running task     stack:27368 pid:11953 ppid:  3610 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5000 [inline]
 __schedule+0xab2/0x4db0 kernel/sched/core.c:6309
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6474
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 vprintk_emit+0x1c9/0x4f0 kernel/printk/printk.c:2249
 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50
 _printk+0xba/0xed kernel/printk/printk.c:2269
 warn_alloc.cold+0x96/0x189 mm/page_alloc.c:4291
 __vmalloc_area_node mm/vmalloc.c:3003 [inline]
 __vmalloc_node_range+0xeb5/0x1130 mm/vmalloc.c:3157
 __vmalloc_node mm/vmalloc.c:3222 [inline]
 vzalloc+0x67/0x80 mm/vmalloc.c:3292
 n_tty_open+0x16/0x170 drivers/tty/n_tty.c:1813
 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:433
 tty_ldisc_setup+0x43/0x100 drivers/tty/tty_ldisc.c:740
 tty_init_dev.part.0+0x1f4/0x610 drivers/tty/tty_io.c:1443
 tty_init_dev+0x5b/0x80 drivers/tty/tty_io.c:1409
 ptmx_open drivers/tty/pty.c:834 [inline]
 ptmx_open+0x112/0x360 drivers/tty/pty.c:800
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4b9/0x1240 fs/open.c:957
 do_open fs/namei.c:3476 [inline]
 path_openat+0x1c9e/0x2940 fs/namei.c:3609
 do_filp_open+0x1aa/0x400 fs/namei.c:3636
 do_sys_openat2+0x16d/0x4d0 fs/open.c:1347
 do_sys_open fs/open.c:1363 [inline]
 __do_sys_openat fs/open.c:1379 [inline]
 __se_sys_openat fs/open.c:1374 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1374
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fb79118a059
RSP: 002b:00007fb7900ff168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb79129cf60 RCX: 00007fb79118a059
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: ffffffffffffff9c
RBP: 00007fb7911e408d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdb6890fef R14: 00007fb7900ff300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6463
2 locks held by getty/3273:
 #0: ffff888023d6a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077
3 locks held by syz-executor.3/11953:
1 lock held by syz-executor.1/12201:
 #0: ffffffff8c5b5c28 (tty_mutex){+.+.}-{3:3}, at: ptmx_open drivers/tty/pty.c:833 [inline]
 #0: ffffffff8c5b5c28 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0x103/0x360 drivers/tty/pty.c:800

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