Henry-Hiles/qmk_userspace
1
0
Fork 0
forked from mirrors/qmk_userspace
Code Pull requests Activity

Fix out of bound OLED font access (#8145)

Browse source 
* Fix out of bound OLED font access

The default font is 1344 bytes, or a total of 224 glyphs (each 6-bytes wide).
OLED_FONT_END defaults to 224, which if used will then index off the end of
the font array. So either the documentation or code is wrong.

Instead of figuring out the rewording of the documentation, just change
the OLED_FONT_END default value to 223, to match the documentation and code.

* Add static assert to check array size

Build bomb if the font array size doesn't match to the defines.
This commit is contained in:
Ted M Lin 2020-02-11 16:38:20 -05:00 • committed by GitHub
parent 78e060f55a
commit 9456832a3b
Failed to generate hash of commit
3 changed files with 6 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

4
drivers/oled/oled_driver.c
View file

@ -392,6 +392,8 @@ void oled_write_char(const char data, bool invert) {
static uint8_t oled_temp_buffer[OLED_FONT_WIDTH];
memcpy(&oled_temp_buffer, oled_cursor, OLED_FONT_WIDTH);
_Static_assert(sizeof(font) >= ((OLED_FONT_END + 1 - OLED_FONT_START) * OLED_FONT_WIDTH), "OLED_FONT_END references outside array");
// set the reder buffer data
uint8_t cast_data = (uint8_t)data; // font based on unsigned type for index
if (cast_data < OLED_FONT_START || cast_data > OLED_FONT_END) {
@ -585,4 +587,4 @@ void oled_task(void) {
#endif
}
__attribute__((weak)) void oled_task_user(void) {}
__attribute__((weak)) void oled_task_user(void) {}