1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
From: =?utf-8?b?UGV0ciBQw61zYcWZ?= <ppisar@redhat.com>
Date: Mon, 10 Jun 2019 08:50:59 -0700
Subject: CVE-2019-7574: Fix a buffer overread in IMA_ADPCM_decode
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
If data chunk was shorter than expected based on a WAV format
definition, IMA_ADPCM_decode() tried to read past the data chunk
buffer. This patch fixes it.
Bug: https://bugzilla.libsdl.org/show_bug.cgi?id=4496
Bug-CVE: CVE-2019-7574
Signed-off-by: Petr Písař <ppisar@redhat.com>
Origin: upstream, commit:https://github.com/libsdl-org/SDL-1.2/commit/76871a1c52dc74b8ba2357b9d68c34d765ea9db3
---
src/audio/SDL_wave.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/audio/SDL_wave.c b/src/audio/SDL_wave.c
index 21ee4dc..66f8044 100644
--- a/src/audio/SDL_wave.c
+++ b/src/audio/SDL_wave.c
@@ -331,7 +331,7 @@ static void Fill_IMA_ADPCM_block(Uint8 *decoded, Uint8 *encoded,
static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
{
struct IMA_ADPCM_decodestate *state;
- Uint8 *freeable, *encoded, *decoded;
+ Uint8 *freeable, *encoded, *encoded_end, *decoded;
Sint32 encoded_len, samplesleft;
unsigned int c, channels;
@@ -347,6 +347,7 @@ static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
/* Allocate the proper sized output buffer */
encoded_len = *audio_len;
encoded = *audio_buf;
+ encoded_end = encoded + encoded_len;
freeable = *audio_buf;
*audio_len = (encoded_len/IMA_ADPCM_state.wavefmt.blockalign) *
IMA_ADPCM_state.wSamplesPerBlock*
@@ -362,6 +363,7 @@ static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
while ( encoded_len >= IMA_ADPCM_state.wavefmt.blockalign ) {
/* Grab the initial information for this block */
for ( c=0; c<channels; ++c ) {
+ if (encoded + 4 > encoded_end) goto invalid_size;
/* Fill the state information for this block */
state[c].sample = ((encoded[1]<<8)|encoded[0]);
encoded += 2;
@@ -384,6 +386,7 @@ static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
samplesleft = (IMA_ADPCM_state.wSamplesPerBlock-1)*channels;
while ( samplesleft > 0 ) {
for ( c=0; c<channels; ++c ) {
+ if (encoded + 4 > encoded_end) goto invalid_size;
Fill_IMA_ADPCM_block(decoded, encoded,
c, channels, &state[c]);
encoded += 4;
@@ -395,6 +398,10 @@ static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
}
SDL_free(freeable);
return(0);
+invalid_size:
+ SDL_SetError("Unexpected chunk length for an IMA ADPCM decoder");
+ SDL_free(freeable);
+ return(-1);
}
SDL_AudioSpec * SDL_LoadWAV_RW (SDL_RWops *src, int freesrc,
|
