| # HG changeset patch |
| # User Petr Písař <ppisar@redhat.com> |
| # Date 1560183905 25200 |
| # Mon Jun 10 09:25:05 2019 -0700 |
| # Branch SDL-1.2 |
| # Node ID a936f9bd3e381d67d8ddee8b9243f85799ea4798 |
| # Parent fcbecae427951bac1684baaba2ade68221315140 |
| CVE-2019-7575: Fix a buffer overwrite in MS_ADPCM_decode |
| If a WAV format defines shorter audio stream and decoded MS ADPCM data chunk |
| is longer, decoding continued past the output audio buffer. |
| |
| This fix is based on a patch from |
| <https://bugzilla.libsdl.org/show_bug.cgi?id=4492>. |
| |
| https://bugzilla.libsdl.org/show_bug.cgi?id=4493 |
| CVE-2019-7575 |
| |
| Signed-off-by: Petr Písař <ppisar@redhat.com> |
| |
| CVE: CVE-2019-7575 |
| Upstream-Status: Backport |
| Signed-off-by: Anuj Mittal <anuj.mittal@intel.com> |
| |
| diff -r fcbecae42795 -r a936f9bd3e38 src/audio/SDL_wave.c |
| --- a/src/audio/SDL_wave.c Mon Jun 10 09:06:23 2019 -0700 |
| +++ b/src/audio/SDL_wave.c Mon Jun 10 09:25:05 2019 -0700 |
| @@ -122,7 +122,7 @@ |
| static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len) |
| { |
| struct MS_ADPCM_decodestate *state[2]; |
| - Uint8 *freeable, *encoded, *encoded_end, *decoded; |
| + Uint8 *freeable, *encoded, *encoded_end, *decoded, *decoded_end; |
| Sint32 encoded_len, samplesleft; |
| Sint8 nybble, stereo; |
| Sint16 *coeff[2]; |
| @@ -142,6 +142,7 @@ |
| return(-1); |
| } |
| decoded = *audio_buf; |
| + decoded_end = decoded + *audio_len; |
| |
| /* Get ready... Go! */ |
| stereo = (MS_ADPCM_state.wavefmt.channels == 2); |
| @@ -149,7 +150,7 @@ |
| state[1] = &MS_ADPCM_state.state[stereo]; |
| while ( encoded_len >= MS_ADPCM_state.wavefmt.blockalign ) { |
| /* Grab the initial information for this block */ |
| - if (encoded + 7 + (stereo ? 7 : 0) > encoded_end) goto too_short; |
| + if (encoded + 7 + (stereo ? 7 : 0) > encoded_end) goto invalid_size; |
| state[0]->hPredictor = *encoded++; |
| if ( stereo ) { |
| state[1]->hPredictor = *encoded++; |
| @@ -179,6 +180,7 @@ |
| coeff[1] = MS_ADPCM_state.aCoeff[state[1]->hPredictor]; |
| |
| /* Store the two initial samples we start with */ |
| + if (decoded + 4 + (stereo ? 4 : 0) > decoded_end) goto invalid_size; |
| decoded[0] = state[0]->iSamp2&0xFF; |
| decoded[1] = state[0]->iSamp2>>8; |
| decoded += 2; |
| @@ -200,7 +202,8 @@ |
| samplesleft = (MS_ADPCM_state.wSamplesPerBlock-2)* |
| MS_ADPCM_state.wavefmt.channels; |
| while ( samplesleft > 0 ) { |
| - if (encoded + 1 > encoded_end) goto too_short; |
| + if (encoded + 1 > encoded_end) goto invalid_size; |
| + if (decoded + 4 > decoded_end) goto invalid_size; |
| |
| nybble = (*encoded)>>4; |
| new_sample = MS_ADPCM_nibble(state[0],nybble,coeff[0]); |
| @@ -223,8 +226,8 @@ |
| } |
| SDL_free(freeable); |
| return(0); |
| -too_short: |
| - SDL_SetError("Too short chunk for a MS ADPCM decoder"); |
| +invalid_size: |
| + SDL_SetError("Unexpected chunk length for a MS ADPCM decoder"); |
| SDL_free(freeable); |
| return(-1); |
| invalid_predictor: |