[PATCH] stm32mp: fix various array bounds checks

[Patrice CHOTARD]

Hi Rasmus

On 3/24/23 08:55, Rasmus Villemoes wrote:
> In all these cases, the index on the LHS is immediately afterwards
> used to access the array appearing in the ARRAY_SIZE() on the RHS - so
> if that index is equal to the array size, we'll access
> one-past-the-end of the array.
> 
> Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
> ---
> 
> Patch generated with '-U5' to make that access obvious from the diff context.
> 
>  arch/arm/mach-stm32mp/cpu.c                 | 4 ++--
>  board/st/stm32mp1/stm32mp1.c                | 2 +-
>  drivers/ram/stm32mp1/stm32mp1_interactive.c | 2 +-
>  3 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/mach-stm32mp/cpu.c b/arch/arm/mach-stm32mp/cpu.c
> index dc4112d5e6..e2f67fc423 100644
> --- a/arch/arm/mach-stm32mp/cpu.c
> +++ b/arch/arm/mach-stm32mp/cpu.c
> @@ -188,11 +188,11 @@ static void setup_boot_mode(void)
>  
>  	log_debug("%s: boot_ctx=0x%x => boot_mode=%x, instance=%d forced=%x\n",
>  		  __func__, boot_ctx, boot_mode, instance, forced_mode);
>  	switch (boot_mode & TAMP_BOOT_DEVICE_MASK) {
>  	case BOOT_SERIAL_UART:
> -		if (instance > ARRAY_SIZE(serial_addr))
> +		if (instance >= ARRAY_SIZE(serial_addr))
>  			break;
>  		/* serial : search associated node in devicetree */
>  		sprintf(cmd, "serial@%x", serial_addr[instance]);
>  		if (uclass_get_device_by_name(UCLASS_SERIAL, cmd, &dev)) {
>  			/* restore console on error */
> @@ -218,11 +218,11 @@ static void setup_boot_mode(void)
>  		env_set("boot_device", "usb");
>  		env_set("boot_instance", "0");
>  		break;
>  	case BOOT_FLASH_SD:
>  	case BOOT_FLASH_EMMC:
> -		if (instance > ARRAY_SIZE(sdmmc_addr))
> +		if (instance >= ARRAY_SIZE(sdmmc_addr))
>  			break;
>  		/* search associated sdmmc node in devicetree */
>  		sprintf(cmd, "mmc@%x", sdmmc_addr[instance]);
>  		if (uclass_get_device_by_name(UCLASS_MMC, cmd, &dev)) {
>  			printf("mmc%d = %s not found in device tree!\n",
> diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
> index ca8f0255ae..1a1b1844c8 100644
> --- a/board/st/stm32mp1/stm32mp1.c
> +++ b/board/st/stm32mp1/stm32mp1.c
> @@ -870,11 +870,11 @@ int mmc_get_boot(void)
>  		STM32_SDMMC1_BASE,
>  		STM32_SDMMC2_BASE,
>  		STM32_SDMMC3_BASE
>  	};
>  
> -	if (instance > ARRAY_SIZE(sdmmc_addr))
> +	if (instance >= ARRAY_SIZE(sdmmc_addr))
>  		return 0;
>  
>  	/* search associated sdmmc node in devicetree */
>  	snprintf(cmd, sizeof(cmd), "mmc@%x", sdmmc_addr[instance]);
>  	if (uclass_get_device_by_name(UCLASS_MMC, cmd, &dev)) {
> diff --git a/drivers/ram/stm32mp1/stm32mp1_interactive.c b/drivers/ram/stm32mp1/stm32mp1_interactive.c
> index f0fe7e61e3..2c19847c66 100644
> --- a/drivers/ram/stm32mp1/stm32mp1_interactive.c
> +++ b/drivers/ram/stm32mp1/stm32mp1_interactive.c
> @@ -389,11 +389,11 @@ bool stm32mp1_ddr_interactive(void *priv,
>  	log_debug("** step %d ** %s / %d\n", step, step_str[step], next_step);
>  
>  	if (next_step < 0)
>  		return false;
>  
> -	if (step < 0 || step > ARRAY_SIZE(step_str)) {
> +	if (step < 0 || step >= ARRAY_SIZE(step_str)) {
>  		printf("** step %d ** INVALID\n", step);
>  		return false;
>  	}
>  
>  	printf("%d:%s\n", step, step_str[step]);

Good catch !

Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>

Thanks
Patrice