| Brad Bishop | 26bdd44 | 2019-08-16 17:08:17 -0400 | [diff] [blame^] | 1 | # HG changeset patch |
| 2 | # User Petr Písař <ppisar@redhat.com> |
| 3 | # Date 1560182051 25200 |
| 4 | # Mon Jun 10 08:54:11 2019 -0700 |
| 5 | # Branch SDL-1.2 |
| 6 | # Node ID 416136310b88cbeeff8773e573e90ac1e22b3526 |
| 7 | # Parent a6e3d2f5183e1cc300ad993e10e9ce077e13bd9c |
| 8 | CVE-2019-7577: Fix a buffer overread in MS_ADPCM_decode |
| 9 | If RIFF/WAV data chunk length is shorter then expected for an audio |
| 10 | format defined in preceeding RIFF/WAV format headers, a buffer |
| 11 | overread can happen. |
| 12 | |
| 13 | This patch fixes it by checking a MS ADPCM data to be decoded are not |
| 14 | past the initialized buffer. |
| 15 | |
| 16 | CVE-2019-7577 |
| 17 | Reproducer: https://bugzilla.libsdl.org/show_bug.cgi?id=4492 |
| 18 | |
| 19 | Signed-off-by: Petr Písař <ppisar@redhat.com> |
| 20 | |
| 21 | # HG changeset patch |
| 22 | # User Petr Písař <ppisar@redhat.com> |
| 23 | # Date 1560182069 25200 |
| 24 | # Mon Jun 10 08:54:29 2019 -0700 |
| 25 | # Branch SDL-1.2 |
| 26 | # Node ID faf9abbcfb5fe0d0ca23c4bf0394aa226ceccf02 |
| 27 | # Parent 416136310b88cbeeff8773e573e90ac1e22b3526 |
| 28 | CVE-2019-7577: Fix a buffer overread in MS_ADPCM_nibble and MS_ADPCM_decode |
| 29 | If a chunk of RIFF/WAV file with MS ADPCM encoding contains an invalid |
| 30 | predictor (a valid predictor's value is between 0 and 6 inclusive), |
| 31 | a buffer overread can happen when the predictor is used as an index |
| 32 | into an array of MS ADPCM coefficients. |
| 33 | |
| 34 | The overead happens when indexing MS_ADPCM_state.aCoeff[] array in |
| 35 | MS_ADPCM_decode() and later when dereferencing a coef pointer in |
| 36 | MS_ADPCM_nibble(). |
| 37 | |
| 38 | This patch fixes it by checking the MS ADPCM predictor values fit |
| 39 | into the valid range. |
| 40 | |
| 41 | CVE-2019-7577 |
| 42 | Reproducer: https://bugzilla.libsdl.org/show_bug.cgi?id=4492 |
| 43 | |
| 44 | Signed-off-by: Petr Písař <ppisar@redhat.com> |
| 45 | |
| 46 | CVE: CVE-2019-7577 |
| 47 | Upstream-Status: Backport |
| 48 | Signed-off-by: Anuj Mittal <anuj.mittal@intel.com> |
| 49 | |
| 50 | diff -r a6e3d2f5183e -r 416136310b88 src/audio/SDL_wave.c |
| 51 | --- a/src/audio/SDL_wave.c Mon Jun 10 08:50:59 2019 -0700 |
| 52 | +++ b/src/audio/SDL_wave.c Mon Jun 10 08:54:11 2019 -0700 |
| 53 | @@ -115,7 +115,7 @@ |
| 54 | static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len) |
| 55 | { |
| 56 | struct MS_ADPCM_decodestate *state[2]; |
| 57 | - Uint8 *freeable, *encoded, *decoded; |
| 58 | + Uint8 *freeable, *encoded, *encoded_end, *decoded; |
| 59 | Sint32 encoded_len, samplesleft; |
| 60 | Sint8 nybble, stereo; |
| 61 | Sint16 *coeff[2]; |
| 62 | @@ -124,6 +124,7 @@ |
| 63 | /* Allocate the proper sized output buffer */ |
| 64 | encoded_len = *audio_len; |
| 65 | encoded = *audio_buf; |
| 66 | + encoded_end = encoded + encoded_len; |
| 67 | freeable = *audio_buf; |
| 68 | *audio_len = (encoded_len/MS_ADPCM_state.wavefmt.blockalign) * |
| 69 | MS_ADPCM_state.wSamplesPerBlock* |
| 70 | @@ -141,6 +142,7 @@ |
| 71 | state[1] = &MS_ADPCM_state.state[stereo]; |
| 72 | while ( encoded_len >= MS_ADPCM_state.wavefmt.blockalign ) { |
| 73 | /* Grab the initial information for this block */ |
| 74 | + if (encoded + 7 + (stereo ? 7 : 0) > encoded_end) goto too_short; |
| 75 | state[0]->hPredictor = *encoded++; |
| 76 | if ( stereo ) { |
| 77 | state[1]->hPredictor = *encoded++; |
| 78 | @@ -188,6 +190,8 @@ |
| 79 | samplesleft = (MS_ADPCM_state.wSamplesPerBlock-2)* |
| 80 | MS_ADPCM_state.wavefmt.channels; |
| 81 | while ( samplesleft > 0 ) { |
| 82 | + if (encoded + 1 > encoded_end) goto too_short; |
| 83 | + |
| 84 | nybble = (*encoded)>>4; |
| 85 | new_sample = MS_ADPCM_nibble(state[0],nybble,coeff[0]); |
| 86 | decoded[0] = new_sample&0xFF; |
| 87 | @@ -209,6 +213,10 @@ |
| 88 | } |
| 89 | SDL_free(freeable); |
| 90 | return(0); |
| 91 | +too_short: |
| 92 | + SDL_SetError("Too short chunk for a MS ADPCM decoder"); |
| 93 | + SDL_free(freeable); |
| 94 | + return(-1); |
| 95 | } |
| 96 | |
| 97 | struct IMA_ADPCM_decodestate { |
| 98 | |
| 99 | |
| 100 | diff -r 416136310b88 -r faf9abbcfb5f src/audio/SDL_wave.c |
| 101 | --- a/src/audio/SDL_wave.c Mon Jun 10 08:54:11 2019 -0700 |
| 102 | +++ b/src/audio/SDL_wave.c Mon Jun 10 08:54:29 2019 -0700 |
| 103 | @@ -147,6 +147,9 @@ |
| 104 | if ( stereo ) { |
| 105 | state[1]->hPredictor = *encoded++; |
| 106 | } |
| 107 | + if (state[0]->hPredictor >= 7 || state[1]->hPredictor >= 7) { |
| 108 | + goto invalid_predictor; |
| 109 | + } |
| 110 | state[0]->iDelta = ((encoded[1]<<8)|encoded[0]); |
| 111 | encoded += sizeof(Sint16); |
| 112 | if ( stereo ) { |
| 113 | @@ -217,6 +220,10 @@ |
| 114 | SDL_SetError("Too short chunk for a MS ADPCM decoder"); |
| 115 | SDL_free(freeable); |
| 116 | return(-1); |
| 117 | +invalid_predictor: |
| 118 | + SDL_SetError("Invalid predictor value for a MS ADPCM decoder"); |
| 119 | + SDL_free(freeable); |
| 120 | + return(-1); |
| 121 | } |
| 122 | |
| 123 | struct IMA_ADPCM_decodestate { |