From 450aaae8638e4c75ac6547ce6e09d63281a5a925 Mon Sep 17 00:00:00 2001 From: Alistair Francis Date: Tue, 27 Dec 2016 14:59:22 +0000 Subject: cadence_uart: Check baud rate generator and divider values on migration The Cadence UART device emulator calculates speed by dividing the baud rate by a 'baud rate generator' & 'baud rate divider' value. The device specification defines these register values to be non-zero and within certain limits. Checks were recently added when writing to these registers but not when restoring from migration. This patch adds checks when restoring from migration to avoid divide by zero errors. Reported-by: Huawei PSIRT Signed-off-by: Alistair Francis Message-id: 04ae30ed8ee1758cd2d2af880da4d28f74c67738.1481132150.git.alistair.francis@xilinx.com Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/char/cadence_uart.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'hw/char') diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c index 0215d6518d..dba1c53586 100644 --- a/hw/char/cadence_uart.c +++ b/hw/char/cadence_uart.c @@ -502,6 +502,13 @@ static int cadence_uart_post_load(void *opaque, int version_id) { CadenceUARTState *s = opaque; + /* Ensure these two aren't invalid numbers */ + if (s->r[R_BRGR] < 1 || s->r[R_BRGR] & ~0xFFFF || + s->r[R_BDIV] <= 3 || s->r[R_BDIV] & ~0xFF) { + /* Value is invalid, abort */ + return 1; + } + uart_parameters_setup(s); uart_update_status(s); return 0; -- cgit v1.2.3