58 lines
1.8 KiB
Diff
58 lines
1.8 KiB
Diff
From 69cd6157644cb0a5c9edd7b5920232c2ca31c151 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
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Date: Tue, 12 Mar 2019 16:21:41 +0100
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Subject: [PATCH] CVE-2019-7577: Fix a buffer overread in MS_ADPCM_nibble and
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MS_ADPCM_decode
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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If a chunk of RIFF/WAV file with MS ADPCM encoding contains an invalid
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predictor (a valid predictor's value is between 0 and 6 inclusive),
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a buffer overread can happen when the predictor is used as an index
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into an array of MS ADPCM coefficients.
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The overead happens when indexing MS_ADPCM_state.aCoeff[] array in
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MS_ADPCM_decode() and later when dereferencing a coef pointer in
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MS_ADPCM_nibble().
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This patch fixes it by checking the MS ADPCM predictor values fit
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into the valid range.
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CVE-2019-7577
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Reproducer: https://bugzilla.libsdl.org/show_bug.cgi?id=4492
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Signed-off-by: Petr Písař <ppisar@redhat.com>
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---
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src/audio/SDL_wave.c | 7 +++++++
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1 file changed, 7 insertions(+)
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diff --git a/src/audio/SDL_wave.c b/src/audio/SDL_wave.c
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index 08f65cb..5f93651 100644
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--- a/src/audio/SDL_wave.c
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+++ b/src/audio/SDL_wave.c
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@@ -155,6 +155,9 @@ static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
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if ( stereo ) {
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state[1]->hPredictor = *encoded++;
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}
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+ if (state[0]->hPredictor >= 7 || state[1]->hPredictor >= 7) {
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+ goto invalid_predictor;
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+ }
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state[0]->iDelta = ((encoded[1]<<8)|encoded[0]);
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encoded += sizeof(Sint16);
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if ( stereo ) {
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@@ -227,6 +230,10 @@ invalid_size:
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SDL_SetError("Unexpected chunk length for a MS ADPCM decoder");
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SDL_free(freeable);
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return(-1);
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+invalid_predictor:
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+ SDL_SetError("Invalid predictor value for a MS ADPCM decoder");
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+ SDL_free(freeable);
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+ return(-1);
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}
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struct IMA_ADPCM_decodestate {
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--
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2.20.1
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