avcodec/tiff: Check bpp/bppcount for 0

Fixes: division by zero
Fixes: 24253/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-6250318007107584

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/tiff.c

@@ -1290,7 +1290,7 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
         s->height = value;
         break;
     case TIFF_BPP:
-        if (count > 5U) {
+        if (count > 5 || count <= 0) {
             av_log(s->avctx, AV_LOG_ERROR,
                    "This format is not supported (bpp=%d, %d components)\n",
                    value, count);
@@ -1321,9 +1321,9 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
                    "Samples per pixel requires a single value, many provided\n");
             return AVERROR_INVALIDDATA;
         }
-        if (value > 5U) {
+        if (value > 5 || value <= 0) {
             av_log(s->avctx, AV_LOG_ERROR,
-                   "Samples per pixel %d is too large\n", value);
+                   "Invalid samples per pixel %d\n", value);
             return AVERROR_INVALIDDATA;
         }
         if (s->bppcount == 1)