[FFmpeg-devel] [PATCH] vf_unsharp: extend/improve feedback for validity checks

[Stefano Sabatini]

Abort for invalid too big values, and exactly state why the input
value is invalid.

In particular, avoid out-of-buffer access with too big values.
---
 libavfilter/vf_unsharp.c |   20 ++++++++++++++------
 1 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/libavfilter/vf_unsharp.c b/libavfilter/vf_unsharp.c
index e41e76f..9c85e5d 100644
--- a/libavfilter/vf_unsharp.c
+++ b/libavfilter/vf_unsharp.c
@@ -135,19 +135,27 @@ static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
     UnsharpContext *unsharp = ctx->priv;
     int lmsize_x = 5, cmsize_x = 0;
     int lmsize_y = 5, cmsize_y = 0;
+    int val;
     double lamount = 1.0f, camount = 0.0f;
 
     if (args)
         sscanf(args, "%d:%d:%lf:%d:%d:%lf", &lmsize_x, &lmsize_y, &lamount,
                                             &cmsize_x, &cmsize_y, &camount);
 
-    if ((lamount && (lmsize_x < 2 || lmsize_y < 2)) ||
-        (camount && (cmsize_x < 2 || cmsize_y < 2))) {
-        av_log(ctx, AV_LOG_ERROR,
-               "Invalid value <2 for lmsize_x:%d or lmsize_y:%d or cmsize_x:%d or cmsize_y:%d\n",
-               lmsize_x, lmsize_y, cmsize_x, cmsize_y);
-        return AVERROR(EINVAL);
+#define CHECK_SIZE(lc, xy, lc_str)                                      \
+    val = lc##msize_##xy;                                               \
+    if (val < MATRIX_MIN_LINE_SIZE || val > MATRIX_MAX_LINE_SIZE) {     \
+        av_log(ctx, AV_LOG_ERROR,                                       \
+               "Invalid value '%d' for %s %s size, "                    \
+               "must be >= %d and <= %d\n",                             \
+               val, #lc_str, #xy,                                       \
+               MATRIX_MIN_LINE_SIZE, MATRIX_MAX_LINE_SIZE);             \
+        return AVERROR(EINVAL);                                         \
     }
+    CHECK_SIZE(l, x, luma);
+    CHECK_SIZE(l, y, luma);
+    CHECK_SIZE(c, x, chroma);
+    CHECK_SIZE(c, y, chroma);
 
     set_filter_param(&unsharp->luma,   lmsize_x, lmsize_y, lamount);
     set_filter_param(&unsharp->chroma, cmsize_x, cmsize_y, camount);
-- 
1.7.2.5