=====================================================
BUG: KMSAN: uninit-value in gsm1_receive+0x670/0xcc0 drivers/tty/n_gsm.c:2026
 gsm1_receive+0x670/0xcc0 drivers/tty/n_gsm.c:2026
 gsmld_receive_buf+0x276/0x530 drivers/tty/n_gsm.c:2517
 tty_ldisc_receive_buf+0x32a/0x390 drivers/tty/tty_buffer.c:455
 tty_port_default_receive_buf+0x14b/0x1e0 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:471 [inline]
 flush_to_ldisc+0x38b/0x9a0 drivers/tty/tty_buffer.c:521
 process_one_work+0xdb6/0x1820 kernel/workqueue.c:2289
 worker_thread+0x10d0/0x2240 kernel/workqueue.c:2436
 kthread+0x3c7/0x500 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:754 [inline]
 slab_alloc_node mm/slub.c:3231 [inline]
 slab_alloc mm/slub.c:3239 [inline]
 __kmalloc+0xc13/0x12a0 mm/slub.c:4425
 kmalloc include/linux/slab.h:586 [inline]
 tty_buffer_alloc drivers/tty/tty_buffer.c:178 [inline]
 __tty_buffer_request_room+0x4d2/0x900 drivers/tty/tty_buffer.c:274
 __tty_insert_flip_char+0xe5/0x3d0 drivers/tty/tty_buffer.c:392
 tty_insert_flip_char include/linux/tty_flip.h:35 [inline]
 uart_insert_char+0x475/0xb50 drivers/tty/serial/serial_core.c:3158
 serial8250_read_char+0x280/0x820 drivers/tty/serial/8250/8250_port.c:1792
 serial8250_rx_chars drivers/tty/serial/8250/8250_port.c:1807 [inline]
 serial8250_handle_irq+0x532/0x970 drivers/tty/serial/8250/8250_port.c:1948
 serial8250_default_handle_irq+0x180/0x380 drivers/tty/serial/8250/8250_port.c:1970
 serial8250_interrupt+0x103/0x3f0 drivers/tty/serial/8250/8250_core.c:126
 __handle_irq_event_percpu+0x150/0xb60 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0x142/0x390 kernel/irq/handle.c:210
 handle_edge_irq+0x465/0x13e0 kernel/irq/chip.c:817
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 handle_irq arch/x86/kernel/irq.c:231 [inline]
 __common_interrupt+0xf8/0x360 arch/x86/kernel/irq.c:250
 common_interrupt+0xb1/0xd0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40

CPU: 0 PID: 12839 Comm: kworker/u4:23 Not tainted 5.18.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
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