[FFmpeg-cvslog] avcodec/evc_ps: Check num_ref_pic_list_in_sps

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Jul 27 00:14:15 2023 +0200| [cf9cd35aa9d1db9d7b6b3e9207b47432fdb6fe5e] | committer: Michael Niedermayer

avcodec/evc_ps: Check num_ref_pic_list_in_sps

Fixes: out of array write
Fixes: 60798/clusterfuzz-testcase-minimized-ffmpeg_BSF_EVC_FRAME_MERGE_fuzzer-4633529766772736

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cf9cd35aa9d1db9d7b6b3e9207b47432fdb6fe5e
---

 libavcodec/evc.h    | 2 +-
 libavcodec/evc_ps.c | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/libavcodec/evc.h b/libavcodec/evc.h
index d1fdb4fac6..9711c760fe 100644
--- a/libavcodec/evc.h
+++ b/libavcodec/evc.h
@@ -126,7 +126,7 @@ enum {
 
     EVC_MAX_NUM_REF_PICS = 21,
 
-    EVC_MAX_NUM_RPLS = 32,
+    EVC_MAX_NUM_RPLS = 64,
 
     // A.4.1: pic_width_in_luma_samples and pic_height_in_luma_samples are
     // constrained to be not greater than sqrt(MaxLumaPs * 8).  Hence height/
diff --git a/libavcodec/evc_ps.c b/libavcodec/evc_ps.c
index 04ee6a45e6..64384a392c 100644
--- a/libavcodec/evc_ps.c
+++ b/libavcodec/evc_ps.c
@@ -243,11 +243,20 @@ int ff_evc_parse_sps(GetBitContext *gb, EVCParamSets *ps)
         sps->rpl1_same_as_rpl0_flag = get_bits1(gb);
         sps->num_ref_pic_list_in_sps[0] = get_ue_golomb(gb);
 
+        if ((unsigned)sps->num_ref_pic_list_in_sps[0] >= EVC_MAX_NUM_RPLS) {
+            ret = AVERROR_INVALIDDATA;
+            goto fail;
+        }
+
         for (int i = 0; i < sps->num_ref_pic_list_in_sps[0]; ++i)
             ref_pic_list_struct(gb, &sps->rpls[0][i]);
 
         if (!sps->rpl1_same_as_rpl0_flag) {
             sps->num_ref_pic_list_in_sps[1] = get_ue_golomb(gb);
+            if ((unsigned)sps->num_ref_pic_list_in_sps[1] >= EVC_MAX_NUM_RPLS) {
+                ret = AVERROR_INVALIDDATA;
+                goto fail;
+            }
             for (int i = 0; i < sps->num_ref_pic_list_in_sps[1]; ++i)
                 ref_pic_list_struct(gb, &sps->rpls[1][i]);
         }