CVE-2024-43893

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> serial: core: check uartclk for zero to avoid divide by zero<br /> <br /> Calling ioctl TIOCSSERIAL with an invalid baud_base can<br /> result in uartclk being zero, which will result in a<br /> divide by zero error in uart_get_divisor(). The check for<br /> uartclk being zero in uart_set_info() needs to be done<br /> before other settings are made as subsequent calls to<br /> ioctl TIOCSSERIAL for the same port would be impacted if<br /> the uartclk check was done where uartclk gets set.<br /> <br /> Oops: divide error: 0000 PREEMPT SMP KASAN PTI<br /> RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580)<br /> Call Trace:<br /> <br /> serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576<br /> drivers/tty/serial/8250/8250_port.c:2589)<br /> serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502<br /> drivers/tty/serial/8250/8250_port.c:2741)<br /> serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862)<br /> uart_change_line_settings (./include/linux/spinlock.h:376<br /> ./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222)<br /> uart_port_startup (drivers/tty/serial/serial_core.c:342)<br /> uart_startup (drivers/tty/serial/serial_core.c:368)<br /> uart_set_info (drivers/tty/serial/serial_core.c:1034)<br /> uart_set_info_user (drivers/tty/serial/serial_core.c:1059)<br /> tty_set_serial (drivers/tty/tty_io.c:2637)<br /> tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791)<br /> __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907<br /> fs/ioctl.c:893 fs/ioctl.c:893)<br /> do_syscall_64 (arch/x86/entry/common.c:52<br /> (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))<br /> entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)<br /> <br /> Rule: add