From 86ee55e9bc7ff7308eda67e5bcb3f8c834c7c113 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 10 Jan 2024 22:25:21 +0300 Subject: [PATCH] serial: 8250_pci1xxxx: fix off by one in pci1xxxx_process_read_data() These > comparisons should be >= to prevent writing one element beyond the end of the rx_buff[] array. The rx_buff[] buffer has RX_BUF_SIZE elements. Fix the buffer overflow. Fixes: aba8290f368d ("8250: microchip: pci1xxxx: Add Burst mode reception support in uart driver for writing into FIFO") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/ZZ7vIfj7Jgh-pJn8@moroto Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci1xxxx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c index 558c4c7f3104..cd258922bd78 100644 --- a/drivers/tty/serial/8250/8250_pci1xxxx.c +++ b/drivers/tty/serial/8250/8250_pci1xxxx.c @@ -302,7 +302,7 @@ static void pci1xxxx_process_read_data(struct uart_port *port, * to read, the data is received one byte at a time. */ while (valid_burst_count--) { - if (*buff_index > (RX_BUF_SIZE - UART_BURST_SIZE)) + if (*buff_index >= (RX_BUF_SIZE - UART_BURST_SIZE)) break; burst_buf = (u32 *)&rx_buff[*buff_index]; *burst_buf = readl(port->membase + UART_RX_BURST_FIFO); @@ -311,7 +311,7 @@ static void pci1xxxx_process_read_data(struct uart_port *port, } while (*valid_byte_count) { - if (*buff_index > RX_BUF_SIZE) + if (*buff_index >= RX_BUF_SIZE) break; rx_buff[*buff_index] = readb(port->membase + UART_RX_BYTE_FIFO);