[FFmpeg-devel,3/4] avcodec/sbcdec: Fix integer overflows in sbc_synthesize_four()

Submitted by Michael Niedermayer on Oct. 22, 2019, 2:27 p.m.

Details

Message ID 20191022142704.8818-3-michael@niedermayer.cc
State Accepted
Commit 00e469fb6123df92ec3c54ab3b37f77e21d297be
Headers show

Commit Message

Michael Niedermayer Oct. 22, 2019, 2:27 p.m.
Fixes: signed integer overflow: 1494495519 + 1494495519 cannot be represented in type 'int'
Fixes: 18347/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SBC_fuzzer-5711714661695488

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/sbcdec.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

Comments

Michael Niedermayer Nov. 9, 2019, 5:01 p.m.
On Tue, Oct 22, 2019 at 04:27:03PM +0200, Michael Niedermayer wrote:
> Fixes: signed integer overflow: 1494495519 + 1494495519 cannot be represented in type 'int'
> Fixes: 18347/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SBC_fuzzer-5711714661695488
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/sbcdec.c | 28 ++++++++++++++--------------
>  1 file changed, 14 insertions(+), 14 deletions(-)

will apply

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diff --git a/libavcodec/sbcdec.c b/libavcodec/sbcdec.c
index 23226d5155..d8ea6855fe 100644
--- a/libavcodec/sbcdec.c
+++ b/libavcodec/sbcdec.c
@@ -227,10 +227,10 @@  static inline void sbc_synthesize_four(struct sbc_decoder_state *state,
 
         /* Distribute the new matrix value to the shifted position */
         v[offset[i]] =
-            ( ff_synmatrix4[i][0] * frame->sb_sample[blk][ch][0] +
-              ff_synmatrix4[i][1] * frame->sb_sample[blk][ch][1] +
-              ff_synmatrix4[i][2] * frame->sb_sample[blk][ch][2] +
-              ff_synmatrix4[i][3] * frame->sb_sample[blk][ch][3] ) >> 15;
+            (int)( (unsigned)ff_synmatrix4[i][0] * frame->sb_sample[blk][ch][0] +
+                   (unsigned)ff_synmatrix4[i][1] * frame->sb_sample[blk][ch][1] +
+                   (unsigned)ff_synmatrix4[i][2] * frame->sb_sample[blk][ch][2] +
+                   (unsigned)ff_synmatrix4[i][3] * frame->sb_sample[blk][ch][3] ) >> 15;
     }
 
     /* Compute the samples */
@@ -239,16 +239,16 @@  static inline void sbc_synthesize_four(struct sbc_decoder_state *state,
 
         /* Store in output, Q0 */
         AV_WN16A(&output_frame->data[ch][blk * 8 + i * 2], av_clip_int16(
-            ( v[offset[i] + 0] * ff_sbc_proto_4_40m0[idx + 0] +
-              v[offset[k] + 1] * ff_sbc_proto_4_40m1[idx + 0] +
-              v[offset[i] + 2] * ff_sbc_proto_4_40m0[idx + 1] +
-              v[offset[k] + 3] * ff_sbc_proto_4_40m1[idx + 1] +
-              v[offset[i] + 4] * ff_sbc_proto_4_40m0[idx + 2] +
-              v[offset[k] + 5] * ff_sbc_proto_4_40m1[idx + 2] +
-              v[offset[i] + 6] * ff_sbc_proto_4_40m0[idx + 3] +
-              v[offset[k] + 7] * ff_sbc_proto_4_40m1[idx + 3] +
-              v[offset[i] + 8] * ff_sbc_proto_4_40m0[idx + 4] +
-              v[offset[k] + 9] * ff_sbc_proto_4_40m1[idx + 4] ) >> 15));
+         (int)( (unsigned)v[offset[i] + 0] * ff_sbc_proto_4_40m0[idx + 0] +
+                (unsigned)v[offset[k] + 1] * ff_sbc_proto_4_40m1[idx + 0] +
+                (unsigned)v[offset[i] + 2] * ff_sbc_proto_4_40m0[idx + 1] +
+                (unsigned)v[offset[k] + 3] * ff_sbc_proto_4_40m1[idx + 1] +
+                (unsigned)v[offset[i] + 4] * ff_sbc_proto_4_40m0[idx + 2] +
+                (unsigned)v[offset[k] + 5] * ff_sbc_proto_4_40m1[idx + 2] +
+                (unsigned)v[offset[i] + 6] * ff_sbc_proto_4_40m0[idx + 3] +
+                (unsigned)v[offset[k] + 7] * ff_sbc_proto_4_40m1[idx + 3] +
+                (unsigned)v[offset[i] + 8] * ff_sbc_proto_4_40m0[idx + 4] +
+                (unsigned)v[offset[k] + 9] * ff_sbc_proto_4_40m1[idx + 4] ) >> 15));
     }
 }