syzbot

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BUG: KMSAN: uninit-value in scan_ordinary drivers/net/ppp/ppp_async.c:746 [inline]
BUG: KMSAN: uninit-value in ppp_async_input drivers/net/ppp/ppp_async.c:846 [inline]
BUG: KMSAN: uninit-value in ppp_asynctty_receive+0x859/0x3710 drivers/net/ppp/ppp_async.c:341
 scan_ordinary drivers/net/ppp/ppp_async.c:746 [inline]
 ppp_async_input drivers/net/ppp/ppp_async.c:846 [inline]
 ppp_asynctty_receive+0x859/0x3710 drivers/net/ppp/ppp_async.c:341
 tty_ldisc_receive_buf+0x1e7/0x270 drivers/tty/tty_buffer.c:391
 tty_port_default_receive_buf+0xdf/0x190 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x4b7/0xdc0 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3e8/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was created at:
 slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 __kmem_cache_alloc_node+0x536/0x8d0 mm/slub.c:3517
 __do_kmalloc_node mm/slab_common.c:1025 [inline]
 __kmalloc+0x121/0x3c0 mm/slab_common.c:1039
 kmalloc include/linux/slab.h:603 [inline]
 tty_buffer_alloc drivers/tty/tty_buffer.c:180 [inline]
 __tty_buffer_request_room+0x36e/0x6c0 drivers/tty/tty_buffer.c:273
 __tty_insert_flip_string_flags+0x140/0x560 drivers/tty/tty_buffer.c:309
 tty_insert_flip_char include/linux/tty_flip.h:77 [inline]
 uart_insert_char+0x39e/0xa00 drivers/tty/serial/serial_core.c:3493
 serial8250_read_char+0x1a2/0x5d0 drivers/tty/serial/8250/8250_port.c:1768
 serial8250_rx_chars drivers/tty/serial/8250/8250_port.c:1785 [inline]
 serial8250_handle_irq+0x77b/0xb30 drivers/tty/serial/8250/8250_port.c:1945
 serial8250_default_handle_irq+0x11a/0x2a0 drivers/tty/serial/8250/8250_port.c:1970
 serial8250_interrupt+0xc0/0x350 drivers/tty/serial/8250/8250_core.c:127
 __handle_irq_event_percpu+0x113/0xc90 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0xef/0x2c0 kernel/irq/handle.c:210
 handle_edge_irq+0x341/0xf90 kernel/irq/chip.c:831
 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
 handle_irq arch/x86/kernel/irq.c:238 [inline]
 __common_interrupt+0x94/0x1f0 arch/x86/kernel/irq.c:257
 common_interrupt+0x89/0xa0 arch/x86/kernel/irq.c:247
 asm_common_interrupt+0x2b/0x40 arch/x86/include/asm/idtentry.h:636

CPU: 1 PID: 2811 Comm: kworker/u4:5 Tainted: G        W          6.6.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events_unbound flush_to_ldisc
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