Hello, syzbot found the following issue on: HEAD commit: e88c4cfcb7b8 Merge tag 'for-6.9-rc5-tag' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1664a5e8980000 kernel config: https://syzkaller.appspot.com/x/.config?x=776c05250f36d55c dashboard link: https://syzkaller.appspot.com/bug?extid=2f64914d6a3a8ce91bdd compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/76771e00ba79/disk-e88c4cfc.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c957ed943a4f/vmlinux-e88c4cfc.xz kernel image: https://storage.googleapis.com/syzbot-assets/e719306ed8e3/bzImage-e88c4cfc.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2f64914d6a3a8ce91bdd@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in gsmld_receive_buf+0x5dc/0x640 drivers/tty/n_gsm.c:3555 gsmld_receive_buf+0x5dc/0x640 drivers/tty/n_gsm.c:3555 tty_ldisc_receive_buf+0x202/0x290 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+0x473/0xdb0 drivers/tty/tty_buffer.c:495 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa81/0x1bd0 kernel/workqueue.c:3335 worker_thread+0xea5/0x1560 kernel/workqueue.c:3416 kthread+0x3e2/0x540 kernel/kthread.c:388 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was created at: slab_post_alloc_hook mm/slub.c:3804 [inline] slab_alloc_node mm/slub.c:3845 [inline] __do_kmalloc_node mm/slub.c:3965 [inline] __kmalloc+0x6e4/0x1000 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] tty_buffer_alloc drivers/tty/tty_buffer.c:180 [inline] __tty_buffer_request_room+0x36e/0x6d0 drivers/tty/tty_buffer.c:273 __tty_insert_flip_string_flags+0x140/0x570 drivers/tty/tty_buffer.c:309 tty_insert_flip_char include/linux/tty_flip.h:77 [inline] uart_insert_char+0x39e/0xa10 drivers/tty/serial/serial_core.c:3558 serial8250_read_char+0x1a7/0x5d0 drivers/tty/serial/8250/8250_port.c:1750 serial8250_rx_chars drivers/tty/serial/8250/8250_port.c:1767 [inline] serial8250_handle_irq+0x77a/0xb80 drivers/tty/serial/8250/8250_port.c:1927 serial8250_default_handle_irq+0x120/0x2b0 drivers/tty/serial/8250/8250_port.c:1952 serial8250_interrupt+0xc5/0x360 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x118/0xca0 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+0x340/0xfb0 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+0x97/0x1f0 arch/x86/kernel/irq.c:257 common_interrupt+0x49/0xa0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x2b/0x40 arch/x86/include/asm/idtentry.h:693 CPU: 1 PID: 14392 Comm: kworker/u8:1 Not tainted 6.9.0-rc5-syzkaller-00042-ge88c4cfcb7b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound flush_to_ldisc ===================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
