1*4882a593Smuzhiyun# HG changeset patch
2*4882a593Smuzhiyun# User Petr Písař <ppisar@redhat.com>
3*4882a593Smuzhiyun# Date 1560182231 25200
4*4882a593Smuzhiyun#      Mon Jun 10 08:57:11 2019 -0700
5*4882a593Smuzhiyun# Branch SDL-1.2
6*4882a593Smuzhiyun# Node ID a8afedbcaea0e84921dc770195c4699bda3ccdc5
7*4882a593Smuzhiyun# Parent  faf9abbcfb5fe0d0ca23c4bf0394aa226ceccf02
8*4882a593SmuzhiyunCVE-2019-7572: Fix a buffer overwrite in IMA_ADPCM_decode
9*4882a593SmuzhiyunIf data chunk was longer than expected based on a WAV format
10*4882a593Smuzhiyundefinition, IMA_ADPCM_decode() tried to write past the output
11*4882a593Smuzhiyunbuffer. This patch fixes it.
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunBased on patch from
14*4882a593Smuzhiyun<https://bugzilla.libsdl.org/show_bug.cgi?id=4496>.
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunCVE-2019-7572
17*4882a593Smuzhiyunhttps://bugzilla.libsdl.org/show_bug.cgi?id=4495
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunSigned-off-by: Petr Písař <ppisar@redhat.com>
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun# HG changeset patch
22*4882a593Smuzhiyun# User Petr Písař <ppisar@redhat.com>
23*4882a593Smuzhiyun# Date 1560041863 25200
24*4882a593Smuzhiyun#      Sat Jun 08 17:57:43 2019 -0700
25*4882a593Smuzhiyun# Branch SDL-1.2
26*4882a593Smuzhiyun# Node ID e52413f5258600878f9a10d2f92605a729aa8976
27*4882a593Smuzhiyun# Parent  4e73be7b47877ae11d2279bd916910d469d18f8e
28*4882a593SmuzhiyunCVE-2019-7572: Fix a buffer overread in IMA_ADPCM_nibble
29*4882a593SmuzhiyunIf an IMA ADPCM block contained an initial index out of step table
30*4882a593Smuzhiyunrange (loaded in IMA_ADPCM_decode()), IMA_ADPCM_nibble() blindly used
31*4882a593Smuzhiyunthis bogus value and that lead to a buffer overread.
32*4882a593Smuzhiyun
33*4882a593SmuzhiyunThis patch fixes it by moving clamping the index value at the
34*4882a593Smuzhiyunbeginning of IMA_ADPCM_nibble() function instead of the end after
35*4882a593Smuzhiyunan update.
36*4882a593Smuzhiyun
37*4882a593SmuzhiyunCVE-2019-7572
38*4882a593Smuzhiyunhttps://bugzilla.libsdl.org/show_bug.cgi?id=4495
39*4882a593Smuzhiyun
40*4882a593SmuzhiyunSigned-off-by: Petr Písař <ppisar@redhat.com>
41*4882a593Smuzhiyun
42*4882a593SmuzhiyunCVE: CVE-2019-7572
43*4882a593SmuzhiyunUpstream-Status: Backport
44*4882a593SmuzhiyunSigned-off-by: Anuj Mittal <anuj.mittal@intel.com>
45*4882a593Smuzhiyun
46*4882a593Smuzhiyundiff -r faf9abbcfb5f -r a8afedbcaea0 src/audio/SDL_wave.c
47*4882a593Smuzhiyun--- a/src/audio/SDL_wave.c	Mon Jun 10 08:54:29 2019 -0700
48*4882a593Smuzhiyun+++ b/src/audio/SDL_wave.c	Mon Jun 10 08:57:11 2019 -0700
49*4882a593Smuzhiyun@@ -346,7 +346,7 @@
50*4882a593Smuzhiyun static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
51*4882a593Smuzhiyun {
52*4882a593Smuzhiyun 	struct IMA_ADPCM_decodestate *state;
53*4882a593Smuzhiyun-	Uint8 *freeable, *encoded, *encoded_end, *decoded;
54*4882a593Smuzhiyun+	Uint8 *freeable, *encoded, *encoded_end, *decoded, *decoded_end;
55*4882a593Smuzhiyun 	Sint32 encoded_len, samplesleft;
56*4882a593Smuzhiyun 	unsigned int c, channels;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun@@ -373,6 +373,7 @@
59*4882a593Smuzhiyun 		return(-1);
60*4882a593Smuzhiyun 	}
61*4882a593Smuzhiyun 	decoded = *audio_buf;
62*4882a593Smuzhiyun+	decoded_end = decoded + *audio_len;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun 	/* Get ready... Go! */
65*4882a593Smuzhiyun 	while ( encoded_len >= IMA_ADPCM_state.wavefmt.blockalign ) {
66*4882a593Smuzhiyun@@ -392,6 +393,7 @@
67*4882a593Smuzhiyun 			}
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun 			/* Store the initial sample we start with */
70*4882a593Smuzhiyun+			if (decoded + 2 > decoded_end) goto invalid_size;
71*4882a593Smuzhiyun 			decoded[0] = (Uint8)(state[c].sample&0xFF);
72*4882a593Smuzhiyun 			decoded[1] = (Uint8)(state[c].sample>>8);
73*4882a593Smuzhiyun 			decoded += 2;
74*4882a593Smuzhiyun@@ -402,6 +404,8 @@
75*4882a593Smuzhiyun 		while ( samplesleft > 0 ) {
76*4882a593Smuzhiyun 			for ( c=0; c<channels; ++c ) {
77*4882a593Smuzhiyun 				if (encoded + 4 > encoded_end) goto invalid_size;
78*4882a593Smuzhiyun+				if (decoded + 4 * 4 * channels > decoded_end)
79*4882a593Smuzhiyun+					goto invalid_size;
80*4882a593Smuzhiyun 				Fill_IMA_ADPCM_block(decoded, encoded,
81*4882a593Smuzhiyun 						c, channels, &state[c]);
82*4882a593Smuzhiyun 				encoded += 4;
83*4882a593Smuzhiyun
84*4882a593Smuzhiyundiff -r 4e73be7b4787 -r e52413f52586 src/audio/SDL_wave.c
85*4882a593Smuzhiyun--- a/src/audio/SDL_wave.c	Sat Jun 01 18:27:46 2019 +0100
86*4882a593Smuzhiyun+++ b/src/audio/SDL_wave.c	Sat Jun 08 17:57:43 2019 -0700
87*4882a593Smuzhiyun@@ -264,6 +264,14 @@
88*4882a593Smuzhiyun 	};
89*4882a593Smuzhiyun 	Sint32 delta, step;
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun+	/* Clamp index value. The inital value can be invalid. */
92*4882a593Smuzhiyun+	if ( state->index > 88 ) {
93*4882a593Smuzhiyun+		state->index = 88;
94*4882a593Smuzhiyun+	} else
95*4882a593Smuzhiyun+	if ( state->index < 0 ) {
96*4882a593Smuzhiyun+		state->index = 0;
97*4882a593Smuzhiyun+	}
98*4882a593Smuzhiyun+
99*4882a593Smuzhiyun 	/* Compute difference and new sample value */
100*4882a593Smuzhiyun 	step = step_table[state->index];
101*4882a593Smuzhiyun 	delta = step >> 3;
102*4882a593Smuzhiyun@@ -275,12 +283,6 @@
103*4882a593Smuzhiyun
104*4882a593Smuzhiyun 	/* Update index value */
105*4882a593Smuzhiyun 	state->index += index_table[nybble];
106*4882a593Smuzhiyun-	if ( state->index > 88 ) {
107*4882a593Smuzhiyun-		state->index = 88;
108*4882a593Smuzhiyun-	} else
109*4882a593Smuzhiyun-	if ( state->index < 0 ) {
110*4882a593Smuzhiyun-		state->index = 0;
111*4882a593Smuzhiyun-	}
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun 	/* Clamp output sample */
114*4882a593Smuzhiyun 	if ( state->sample > max_audioval ) {
115