===================================================== BUG: KMSAN: uninit-value in variable_test_bit arch/x86/include/asm/bitops.h:227 [inline] BUG: KMSAN: uninit-value in arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] BUG: KMSAN: uninit-value in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] BUG: KMSAN: uninit-value in n_tty_receive_buf_standard+0xafd/0x98a0 drivers/tty/n_tty.c:1587 variable_test_bit arch/x86/include/asm/bitops.h:227 [inline] arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] n_tty_receive_buf_standard+0xafd/0x98a0 drivers/tty/n_tty.c:1587 __receive_buf drivers/tty/n_tty.c:1624 [inline] n_tty_receive_buf_common+0x1a68/0x2540 drivers/tty/n_tty.c:1723 n_tty_receive_buf2+0x4c/0x60 drivers/tty/n_tty.c:1769 tty_ldisc_receive_buf+0xc3/0x2c0 drivers/tty/tty_buffer.c:387 tty_port_default_receive_buf+0xd7/0x1a0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x44c/0xdb0 drivers/tty/tty_buffer.c:495 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xb97/0x1d90 kernel/workqueue.c:3319 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400 kthread+0xd59/0xf00 kernel/kthread.c:464 ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Uninit was stored to memory at: n_tty_receive_buf_standard+0xaf6/0x98a0 arch/x86/include/asm/bitops.h:-1 __receive_buf drivers/tty/n_tty.c:1624 [inline] n_tty_receive_buf_common+0x1a68/0x2540 drivers/tty/n_tty.c:1723 n_tty_receive_buf2+0x4c/0x60 drivers/tty/n_tty.c:1769 tty_ldisc_receive_buf+0xc3/0x2c0 drivers/tty/tty_buffer.c:387 tty_port_default_receive_buf+0xd7/0x1a0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x44c/0xdb0 drivers/tty/tty_buffer.c:495 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xb97/0x1d90 kernel/workqueue.c:3319 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400 kthread+0xd59/0xf00 kernel/kthread.c:464 ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Uninit was created at: slab_post_alloc_hook mm/slub.c:4167 [inline] slab_alloc_node mm/slub.c:4210 [inline] __do_kmalloc_node mm/slub.c:4340 [inline] __kmalloc_noprof+0x95f/0x1310 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:909 [inline] tty_buffer_alloc drivers/tty/tty_buffer.c:180 [inline] __tty_buffer_request_room+0x3d4/0x7a0 drivers/tty/tty_buffer.c:273 __tty_insert_flip_string_flags+0x157/0x6f0 drivers/tty/tty_buffer.c:309 tty_insert_flip_char include/linux/tty_flip.h:77 [inline] uart_insert_char+0x368/0x930 drivers/tty/serial/serial_core.c:3515 serial8250_read_char+0x1ba/0x670 drivers/tty/serial/8250/8250_port.c:1764 serial8250_rx_chars drivers/tty/serial/8250/8250_port.c:1781 [inline] serial8250_handle_irq+0x930/0x1110 drivers/tty/serial/8250/8250_port.c:1945 serial8250_default_handle_irq+0x116/0x2b0 drivers/tty/serial/8250/8250_port.c:1970 serial8250_interrupt+0xc8/0x400 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x11c/0xbf0 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xe0/0x2a0 kernel/irq/handle.c:210 handle_edge_irq+0x450/0xfd0 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:266 [inline] __common_interrupt+0x9f/0x220 arch/x86/kernel/irq.c:292 common_interrupt+0x94/0xb0 arch/x86/kernel/irq.c:285 asm_common_interrupt+0x2b/0x40 arch/x86/include/asm/idtentry.h:693 CPU: 1 UID: 0 PID: 3994 Comm: kworker/u8:19 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(undef) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: events_unbound flush_to_ldisc =====================================================