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lcd: Fix incorrect use of LCD_STRIDEFORMAT for remote LCDs

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The get_address_fn implementations for some remote LCDs were
checking LCD_STRIDEFORMAT unconditionally, but that macro is
only valid for the main LCD. The remote LCD code only supports
horizontal strides, so when compiling for a remote LCD, force
the use of horizontal stride addressing.

This fixes a buffer overflow and out of bounds write that occurs
with the M:Robe 500 remote LCD. (Tested with sim + ASan only.)

Change-Id: I99c6aa11d38f5105b096fc448948b9ec1b27dfe6
This commit is contained in:
Aidan MacDonald 2022-09-30 10:49:39 +01:00
parent f373c97c90
commit 3bc6408bbe
2 changed files with 2 additions and 2 deletions
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2
firmware/drivers/lcd-1bit-vert.c
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@ -83,7 +83,7 @@ static void *LCDFN(frameaddress_default)(int x, int y)
{
/* the default expects a buffer the same size as the screen */
struct frame_buffer_t *fb = CURRENT_VP->buffer;
#if LCD_STRIDEFORMAT == VERTICAL_STRIDE
#if defined(MAIN_LCD) && LCD_STRIDEFORMAT == VERTICAL_STRIDE
size_t element = (x * LCDM(NATIVE_STRIDE)(fb->stride)) + y;
#else
size_t element = (y * LCDM(NATIVE_STRIDE)(fb->stride)) + x;

2
firmware/drivers/lcd-2bit-vi.c
View file

@ -95,7 +95,7 @@ static void *LCDFN(frameaddress_default)(int x, int y)
{
/* the default expects a buffer the same size as the screen */
struct frame_buffer_t *fb = CURRENT_VP->buffer;
#if LCD_STRIDEFORMAT == VERTICAL_STRIDE
#if defined(MAIN_LCD) && LCD_STRIDEFORMAT == VERTICAL_STRIDE
size_t element = (x * LCDM(NATIVE_STRIDE)(fb->stride)) + y;
#else
size_t element = (y * LCDM(NATIVE_STRIDE)(fb->stride)) + x;