[FFmpeg-devel] [PATCH] libavfilter/vf_drawtext: Add check for av_mallocz() to avoid potential NULL pointer dereference

Jiasheng Jiang jiashengjiangcool at gmail.com
Thu Aug 7 22:02:39 EEST 2025


Add check for the return value of av_mallocz() to avoid potential NULL pointer dereference.

Fixes: 1eeb59a209 ("avfilter/vf_drawtext: improve glyph shaping and positioning")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool at gmail.com>
---
 libavfilter/vf_drawtext.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
index 674e1e53c1..2eb144b5bf 100644
--- a/libavfilter/vf_drawtext.c
+++ b/libavfilter/vf_drawtext.c
@@ -1437,6 +1437,11 @@ continue_on_failed:
     s->line_count = line_count;
     s->lines = av_mallocz(line_count * sizeof(TextLine));
     s->tab_clusters = av_mallocz(s->tab_count * sizeof(uint32_t));
+    if (!s->lines || !s->tab_clusters) {
+        ret = AVERROR(ENOMEM);
+        goto done;
+    }
+
     for (i = 0; i < s->tab_count; ++i) {
         s->tab_clusters[i] = -1;
     }
-- 
2.25.1



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