CVE-2025-39724

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> serial: 8250: fix panic due to PSLVERR<br /> <br /> When the PSLVERR_RESP_EN parameter is set to 1, the device generates<br /> an error response if an attempt is made to read an empty RBR (Receive<br /> Buffer Register) while the FIFO is enabled.<br /> <br /> In serial8250_do_startup(), calling serial_port_out(port, UART_LCR,<br /> UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes<br /> dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter<br /> function enables the FIFO via serial_out(p, UART_FCR, p-&gt;fcr).<br /> Execution proceeds to the serial_port_in(port, UART_RX).<br /> This satisfies the PSLVERR trigger condition.<br /> <br /> When another CPU (e.g., using printk()) is accessing the UART (UART<br /> is busy), the current CPU fails the check (value &amp; ~UART_LCR_SPAR) ==<br /> (lcr &amp; ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter<br /> dw8250_force_idle().<br /> <br /> Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port-&gt;lock<br /> to fix this issue.<br /> <br /> Panic backtrace:<br /> [ 0.442336] Oops - unknown exception [#1]<br /> [ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a<br /> [ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e<br /> ...<br /> [ 0.442416] console_on_rootfs+0x26/0x70