ui/cursor: make width/height unsigned 16-bit integer

Although not actually exploitable at the moment, a negative width/height
could make datasize wrap around and potentially lead to buffer overflow.
Since there is no reason a negative width/height is ever appropriate,
modify QEMUCursor struct and cursor_alloc prototype to accept uint16_t.
This protects us against accidentally introducing future bugs.

Signed-off-by: Mauro Matteo Cascella <mcascell@redhat.com>
Reported-by: Jacek Halon <jacek.halon@gmail.com>
Reported-by: Yair Mizrahi <yairh33@gmail.com>
Reported-by: Elsayed El-Refa'ei <e.elrefaei99@gmail.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230523163023.608121-1-mcascell@redhat.com>
This commit is contained in:
Mauro Matteo Cascella 2023-05-23 18:30:23 +02:00 committed by Marc-André Lureau
parent 1dfea3f212
commit 4c93ce54e7
2 changed files with 4 additions and 3 deletions

View File

@ -144,13 +144,13 @@ typedef struct QemuUIInfo {
/* cursor data format is 32bit RGBA */
typedef struct QEMUCursor {
int width, height;
uint16_t width, height;
int hot_x, hot_y;
int refcount;
uint32_t data[];
} QEMUCursor;
QEMUCursor *cursor_alloc(int width, int height);
QEMUCursor *cursor_alloc(uint16_t width, uint16_t height);
QEMUCursor *cursor_ref(QEMUCursor *c);
void cursor_unref(QEMUCursor *c);
QEMUCursor *cursor_builtin_hidden(void);

View File

@ -90,11 +90,12 @@ QEMUCursor *cursor_builtin_left_ptr(void)
return cursor_parse_xpm(cursor_left_ptr_xpm);
}
QEMUCursor *cursor_alloc(int width, int height)
QEMUCursor *cursor_alloc(uint16_t width, uint16_t height)
{
QEMUCursor *c;
size_t datasize = width * height * sizeof(uint32_t);
/* Modern physical hardware typically uses 512x512 sprites */
if (width > 512 || height > 512) {
return NULL;
}