[FFmpeg-cvslog] avcodec/jpeg2000dec: Fix/check for multiple integer overflows

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Jun 11 22:45:27 2020 +0200| [c579ceffbe30d048c7448c5e9238fc52094de630] | committer: Michael Niedermayer

avcodec/jpeg2000dec: Fix/check for multiple integer overflows

Fixes: shift exponent 35 is too large for 32-bit type 'int'
Fixes: 22857/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_fuzzer-5202709358837760

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c579ceffbe30d048c7448c5e9238fc52094de630
---

 libavcodec/jpeg2000dec.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index b7766459c4..ab36009a2d 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -612,12 +612,19 @@ static int get_rgn(Jpeg2000DecoderContext *s, int n)
     // Currently compno cannot be greater than 4.
     // However, future implementation should support compno up to 65536
     if (compno < s->ncomponents) {
-        if (s->curtileno == -1)
-            s->roi_shift[compno] = bytestream2_get_byte(&s->g);
-        else {
+        int v;
+        if (s->curtileno == -1) {
+            v =  bytestream2_get_byte(&s->g);
+            if (v > 30)
+                return AVERROR_PATCHWELCOME;
+            s->roi_shift[compno] = v;
+        } else {
             if (s->tile[s->curtileno].tp_idx != 0)
                 return AVERROR_INVALIDDATA; // marker occurs only in first tile part of tile
-            s->tile[s->curtileno].comp[compno].roi_shift = bytestream2_get_byte(&s->g);
+            v = bytestream2_get_byte(&s->g);
+            if (v > 30)
+                return AVERROR_PATCHWELCOME;
+            s->tile[s->curtileno].comp[compno].roi_shift = v;
         }
         return 0;
     }
@@ -1669,8 +1676,8 @@ static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
     ff_mqc_initdec(&t1->mqc, cblk->data, 0, 1);
 
     while (passno--) {
-        if (bpno < 0) {
-            av_log(s->avctx, AV_LOG_ERROR, "bpno became negative\n");
+        if (bpno < 0 || bpno > 29) {
+            av_log(s->avctx, AV_LOG_ERROR, "bpno became invalid\n");
             return AVERROR_INVALIDDATA;
         }
         switch(pass_t) {