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backend/drm: fix invalid VLA size in scan_drm_connectors 

I failed to see this issue with Valgrind because of the +1.
This commit is contained in:
emersion 2018-09-02 09:00:21 +02:00
parent 2f0815838d
commit 95d05acda5
1 changed files with 4 additions and 4 deletions
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8
backend/drm/drm.c
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@ -864,13 +864,13 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
return;
}
size_t drm_outputs_len = wl_list_length(&drm->outputs);
size_t seen_len = wl_list_length(&drm->outputs);
// +1 so length can never be 0, which is undefined behaviour.
// Last element isn't used.
bool seen[drm_outputs_len + 1];
bool seen[seen_len + 1];
memset(seen, false, sizeof(seen));
size_t new_outputs_len = 0;
struct wlr_drm_connector *new_outputs[drm_outputs_len + 1];
struct wlr_drm_connector *new_outputs[res->count_connectors + 1];
for (int i = 0; i < res->count_connectors; ++i) {
drmModeConnector *drm_conn = drmModeGetConnector(drm->fd,
@ -998,7 +998,7 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
size_t index = wl_list_length(&drm->outputs);
wl_list_for_each_safe(conn, tmp_conn, &drm->outputs, link) {
index--;
if (index >= drm_outputs_len || seen[index]) {
if (index >= seen_len || seen[index]) {
continue;
}