|
 |
8d63ce |
From e1f80cadb079e35103e6eebf160a818815c823df Mon Sep 17 00:00:00 2001
|
|
|
8d63ce |
From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
|
|
|
8d63ce |
Date: Thu, 14 Feb 2019 14:51:52 +0100
|
|
|
8d63ce |
Subject: [PATCH] CVE-2019-7575: Fix a buffer overwrite in MS_ADPCM_decode
|
|
|
8d63ce |
MIME-Version: 1.0
|
|
|
8d63ce |
Content-Type: text/plain; charset=UTF-8
|
|
|
8d63ce |
Content-Transfer-Encoding: 8bit
|
|
|
8d63ce |
|
|
|
8d63ce |
If a WAV format defines shorter audio stream and decoded MS ADPCM data chunk
|
|
|
8d63ce |
is longer, decoding continued past the output audio buffer.
|
|
|
8d63ce |
|
|
|
8d63ce |
This fix is based on a patch from
|
|
|
8d63ce |
<https://bugzilla.libsdl.org/show_bug.cgi?id=4492>.
|
|
|
8d63ce |
|
|
|
8d63ce |
https://bugzilla.libsdl.org/show_bug.cgi?id=4493
|
|
|
8d63ce |
CVE-2019-7575
|
|
|
8d63ce |
|
|
|
8d63ce |
Signed-off-by: Petr Písař <ppisar@redhat.com>
|
|
|
8d63ce |
---
|
|
|
8d63ce |
src/audio/SDL_wave.c | 13 ++++++++-----
|
|
|
8d63ce |
1 file changed, 8 insertions(+), 5 deletions(-)
|
|
|
8d63ce |
|
|
|
8d63ce |
diff --git a/src/audio/SDL_wave.c b/src/audio/SDL_wave.c
|
|
|
8d63ce |
index e42d01c..b6c49de 100644
|
|
|
8d63ce |
--- a/src/audio/SDL_wave.c
|
|
|
8d63ce |
+++ b/src/audio/SDL_wave.c
|
|
|
8d63ce |
@@ -115,7 +115,7 @@ static Sint32 MS_ADPCM_nibble(struct MS_ADPCM_decodestate *state,
|
|
|
8d63ce |
static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
|
|
|
8d63ce |
{
|
|
|
8d63ce |
struct MS_ADPCM_decodestate *state[2];
|
|
|
8d63ce |
- Uint8 *freeable, *encoded, *encoded_end, *decoded;
|
|
|
8d63ce |
+ Uint8 *freeable, *encoded, *encoded_end, *decoded, *decoded_end;
|
|
|
8d63ce |
Sint32 encoded_len, samplesleft;
|
|
|
8d63ce |
Sint8 nybble, stereo;
|
|
|
8d63ce |
Sint16 *coeff[2];
|
|
|
8d63ce |
@@ -135,6 +135,7 @@ static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
|
|
|
8d63ce |
return(-1);
|
|
|
8d63ce |
}
|
|
|
8d63ce |
decoded = *audio_buf;
|
|
|
8d63ce |
+ decoded_end = decoded + *audio_len;
|
|
|
8d63ce |
|
|
|
8d63ce |
/* Get ready... Go! */
|
|
|
8d63ce |
stereo = (MS_ADPCM_state.wavefmt.channels == 2);
|
|
|
8d63ce |
@@ -142,7 +143,7 @@ static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
|
|
|
8d63ce |
state[1] = &MS_ADPCM_state.state[stereo];
|
|
|
8d63ce |
while ( encoded_len >= MS_ADPCM_state.wavefmt.blockalign ) {
|
|
|
8d63ce |
/* Grab the initial information for this block */
|
|
|
8d63ce |
- if (encoded + 7 + (stereo ? 7 : 0) > encoded_end) goto too_short;
|
|
|
8d63ce |
+ if (encoded + 7 + (stereo ? 7 : 0) > encoded_end) goto invalid_size;
|
|
|
8d63ce |
state[0]->hPredictor = *encoded++;
|
|
|
8d63ce |
if ( stereo ) {
|
|
|
8d63ce |
state[1]->hPredictor = *encoded++;
|
|
|
8d63ce |
@@ -169,6 +170,7 @@ static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
|
|
|
8d63ce |
coeff[1] = MS_ADPCM_state.aCoeff[state[1]->hPredictor];
|
|
|
8d63ce |
|
|
|
8d63ce |
/* Store the two initial samples we start with */
|
|
|
8d63ce |
+ if (decoded + 4 + (stereo ? 4 : 0) > decoded_end) goto invalid_size;
|
|
|
8d63ce |
decoded[0] = state[0]->iSamp2&0xFF;
|
|
|
8d63ce |
decoded[1] = state[0]->iSamp2>>8;
|
|
|
8d63ce |
decoded += 2;
|
|
|
8d63ce |
@@ -190,7 +192,8 @@ static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
|
|
|
8d63ce |
samplesleft = (MS_ADPCM_state.wSamplesPerBlock-2)*
|
|
|
8d63ce |
MS_ADPCM_state.wavefmt.channels;
|
|
|
8d63ce |
while ( samplesleft > 0 ) {
|
|
|
8d63ce |
- if (encoded + 1 > encoded_end) goto too_short;
|
|
|
8d63ce |
+ if (encoded + 1 > encoded_end) goto invalid_size;
|
|
|
8d63ce |
+ if (decoded + 4 > decoded_end) goto invalid_size;
|
|
|
8d63ce |
|
|
|
8d63ce |
nybble = (*encoded)>>4;
|
|
|
8d63ce |
new_sample = MS_ADPCM_nibble(state[0],nybble,coeff[0]);
|
|
|
8d63ce |
@@ -213,8 +216,8 @@ static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
|
|
|
8d63ce |
}
|
|
|
8d63ce |
SDL_free(freeable);
|
|
|
8d63ce |
return(0);
|
|
|
8d63ce |
-too_short:
|
|
|
8d63ce |
- SDL_SetError("Too short chunk for a MS ADPCM decoder");
|
|
|
8d63ce |
+invalid_size:
|
|
|
8d63ce |
+ SDL_SetError("Unexpected chunk length for a MS ADPCM decoder");
|
|
|
8d63ce |
SDL_free(freeable);
|
|
|
8d63ce |
return(-1);
|
|
|
8d63ce |
}
|
|
|
8d63ce |
--
|
|
|
8d63ce |
2.20.1
|
|
|
8d63ce |
|