From 7f4dde33185f820fa37195cc9ab3bc0f4e45b9af Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Mon, 1 Jul 2019 15:43:26 +0300 Subject: [PATCH] package/faad2: add upstream security fixes CVE-2018-20194: Stack buffer overflow on invalid input CVE-2018-20362: Null pointer dereference when processing crafted AAC input Add two more crash fixes from upstream. Signed-off-by: Baruch Siach Signed-off-by: Arnout Vandecappelle (Essensium/Mind) --- ...k-for-syntax-element-inconsistencies.patch | 64 +++++++++++++++++ ...fadj-sanitize-frequency-band-borders.patch | 71 +++++++++++++++++++ .../0003-Fix-a-couple-buffer-overflows.patch | 50 +++++++++++++ ...prevent-crash-on-SCE-followed-by-CPE.patch | 54 ++++++++++++++ 4 files changed, 239 insertions(+) create mode 100644 package/faad2/0001-syntax.c-check-for-syntax-element-inconsistencies.patch create mode 100644 package/faad2/0002-sbr_hfadj-sanitize-frequency-band-borders.patch create mode 100644 package/faad2/0003-Fix-a-couple-buffer-overflows.patch create mode 100644 package/faad2/0004-add-patch-to-prevent-crash-on-SCE-followed-by-CPE.patch diff --git a/package/faad2/0001-syntax.c-check-for-syntax-element-inconsistencies.patch b/package/faad2/0001-syntax.c-check-for-syntax-element-inconsistencies.patch new file mode 100644 index 0000000000..de97dbbaf0 --- /dev/null +++ b/package/faad2/0001-syntax.c-check-for-syntax-element-inconsistencies.patch @@ -0,0 +1,64 @@ +From 466b01d504d7e45f1e9169ac90b3e34ab94aed14 Mon Sep 17 00:00:00 2001 +From: Hugo Lefeuvre +Date: Mon, 25 Feb 2019 10:49:03 +0100 +Subject: [PATCH] syntax.c: check for syntax element inconsistencies + +Implicit channel mapping reconfiguration is explicitely forbidden by +ISO/IEC 13818-7:2006 (8.5.3.3). Decoders should be able to detect such +files and reject them. FAAD2 does not perform any kind of checks +regarding this. + +This leads to security vulnerabilities when processing crafted AAC +files performing such reconfigurations. + +Add checks to decode_sce_lfe and decode_cpe to make sure such +inconsistencies are detected as early as possible. + +These checks first read hDecoder->frame: if this is not the first +frame then we make sure that the syntax element at the same position +in the previous frame also had element_id id_syn_ele. If not, return +21 as this is a fatal file structure issue. + +This patch addresses CVE-2018-20362 (fixes #26) and possibly other +related issues. + +Signed-off-by: Baruch Siach +--- +Upstream status: commit 466b01d504d7 + + libfaad/syntax.c | 12 ++++++++++++ + 1 file changed, 12 insertions(+) + +diff --git a/libfaad/syntax.c b/libfaad/syntax.c +index f8e808c269c0..e7fb11381e46 100644 +--- a/libfaad/syntax.c ++++ b/libfaad/syntax.c +@@ -344,6 +344,12 @@ static void decode_sce_lfe(NeAACDecStruct *hDecoder, + can become 2 when some form of Parametric Stereo coding is used + */ + ++ if (hDecoder->frame && hDecoder->element_id[hDecoder->fr_ch_ele] != id_syn_ele) { ++ /* element inconsistency */ ++ hInfo->error = 21; ++ return; ++ } ++ + /* save the syntax element id */ + hDecoder->element_id[hDecoder->fr_ch_ele] = id_syn_ele; + +@@ -395,6 +401,12 @@ static void decode_cpe(NeAACDecStruct *hDecoder, NeAACDecFrameInfo *hInfo, bitfi + return; + } + ++ if (hDecoder->frame && hDecoder->element_id[hDecoder->fr_ch_ele] != id_syn_ele) { ++ /* element inconsistency */ ++ hInfo->error = 21; ++ return; ++ } ++ + /* save the syntax element id */ + hDecoder->element_id[hDecoder->fr_ch_ele] = id_syn_ele; + +-- +2.20.1 + diff --git a/package/faad2/0002-sbr_hfadj-sanitize-frequency-band-borders.patch b/package/faad2/0002-sbr_hfadj-sanitize-frequency-band-borders.patch new file mode 100644 index 0000000000..9c580f9339 --- /dev/null +++ b/package/faad2/0002-sbr_hfadj-sanitize-frequency-band-borders.patch @@ -0,0 +1,71 @@ +From 6b4a7cde30f2e2cb03e78ef476cc73179cfffda3 Mon Sep 17 00:00:00 2001 +From: Hugo Lefeuvre +Date: Thu, 11 Apr 2019 09:34:07 +0200 +Subject: [PATCH] sbr_hfadj: sanitize frequency band borders + +user passed f_table_lim contains frequency band borders. Frequency +bands are groups of consecutive QMF channels. This means that their +bounds, as provided by f_table_lim, should never exceed MAX_M (maximum +number of QMF channels). c.f. ISO/IEC 14496-3:2001 + +FAAD2 does not verify this, leading to security issues when +processing files defining f_table_lim with values > MAX_M. + +This patch sanitizes the values of f_table_lim so that they can be safely +used as index for Q_M_lim and G_lim arrays. + +Fixes #21 (CVE-2018-20194). + +Signed-off-by: Baruch Siach +--- +Upstream status: commit 6b4a7cde30f2e + + libfaad/sbr_hfadj.c | 18 ++++++++++++++++++ + 1 file changed, 18 insertions(+) + +diff --git a/libfaad/sbr_hfadj.c b/libfaad/sbr_hfadj.c +index 3f310b8190d7..dda1ce8e249b 100644 +--- a/libfaad/sbr_hfadj.c ++++ b/libfaad/sbr_hfadj.c +@@ -485,6 +485,12 @@ static void calculate_gain(sbr_info *sbr, sbr_hfadj_info *adj, uint8_t ch) + ml1 = sbr->f_table_lim[sbr->bs_limiter_bands][k]; + ml2 = sbr->f_table_lim[sbr->bs_limiter_bands][k+1]; + ++ if (ml1 > MAX_M) ++ ml1 = MAX_M; ++ ++ if (ml2 > MAX_M) ++ ml2 = MAX_M; ++ + + /* calculate the accumulated E_orig and E_curr over the limiter band */ + for (m = ml1; m < ml2; m++) +@@ -949,6 +955,12 @@ static void calculate_gain(sbr_info *sbr, sbr_hfadj_info *adj, uint8_t ch) + ml1 = sbr->f_table_lim[sbr->bs_limiter_bands][k]; + ml2 = sbr->f_table_lim[sbr->bs_limiter_bands][k+1]; + ++ if (ml1 > MAX_M) ++ ml1 = MAX_M; ++ ++ if (ml2 > MAX_M) ++ ml2 = MAX_M; ++ + + /* calculate the accumulated E_orig and E_curr over the limiter band */ + for (m = ml1; m < ml2; m++) +@@ -1193,6 +1205,12 @@ static void calculate_gain(sbr_info *sbr, sbr_hfadj_info *adj, uint8_t ch) + ml1 = sbr->f_table_lim[sbr->bs_limiter_bands][k]; + ml2 = sbr->f_table_lim[sbr->bs_limiter_bands][k+1]; + ++ if (ml1 > MAX_M) ++ ml1 = MAX_M; ++ ++ if (ml2 > MAX_M) ++ ml2 = MAX_M; ++ + + /* calculate the accumulated E_orig and E_curr over the limiter band */ + for (m = ml1; m < ml2; m++) +-- +2.20.1 + diff --git a/package/faad2/0003-Fix-a-couple-buffer-overflows.patch b/package/faad2/0003-Fix-a-couple-buffer-overflows.patch new file mode 100644 index 0000000000..6ae7608771 --- /dev/null +++ b/package/faad2/0003-Fix-a-couple-buffer-overflows.patch @@ -0,0 +1,50 @@ +From 942c3e0aee748ea6fe97cb2c1aa5893225316174 Mon Sep 17 00:00:00 2001 +From: Fabian Greffrath +Date: Mon, 10 Jun 2019 13:58:40 +0200 +Subject: [PATCH] Fix a couple buffer overflows + +https://hackerone.com/reports/502816 +https://hackerone.com/reports/507858 + +https://github.com/videolan/vlc/blob/master/contrib/src/faad2/faad2-fix-overflows.patch + +Signed-off-by: Baruch Siach +--- +Upstream status: commit 942c3e0aee748ea6 + + libfaad/bits.c | 5 ++++- + libfaad/syntax.c | 2 ++ + 2 files changed, 6 insertions(+), 1 deletion(-) + +diff --git a/libfaad/bits.c b/libfaad/bits.c +index dc14d7a03952..4c0de24a5d9c 100644 +--- a/libfaad/bits.c ++++ b/libfaad/bits.c +@@ -167,7 +167,10 @@ void faad_resetbits(bitfile *ld, int bits) + int words = bits >> 5; + int remainder = bits & 0x1F; + +- ld->bytes_left = ld->buffer_size - words*4; ++ if (ld->buffer_size < words * 4) ++ ld->bytes_left = 0; ++ else ++ ld->bytes_left = ld->buffer_size - words*4; + + if (ld->bytes_left >= 4) + { +diff --git a/libfaad/syntax.c b/libfaad/syntax.c +index e7fb11381e46..c9925435dbd0 100644 +--- a/libfaad/syntax.c ++++ b/libfaad/syntax.c +@@ -2304,6 +2304,8 @@ static uint8_t excluded_channels(bitfile *ld, drc_info *drc) + while ((drc->additional_excluded_chns[n-1] = faad_get1bit(ld + DEBUGVAR(1,104,"excluded_channels(): additional_excluded_chns"))) == 1) + { ++ if (i >= MAX_CHANNELS - num_excl_chan - 7) ++ return n; + for (i = num_excl_chan; i < num_excl_chan+7; i++) + { + drc->exclude_mask[i] = faad_get1bit(ld +-- +2.20.1 + diff --git a/package/faad2/0004-add-patch-to-prevent-crash-on-SCE-followed-by-CPE.patch b/package/faad2/0004-add-patch-to-prevent-crash-on-SCE-followed-by-CPE.patch new file mode 100644 index 0000000000..b759b037e0 --- /dev/null +++ b/package/faad2/0004-add-patch-to-prevent-crash-on-SCE-followed-by-CPE.patch @@ -0,0 +1,54 @@ +From f1f8e002622196de3aa650163e5dc2888ebc7a63 Mon Sep 17 00:00:00 2001 +From: Fabian Greffrath +Date: Mon, 10 Jun 2019 13:59:49 +0200 +Subject: [PATCH] add patch to prevent crash on SCE followed by CPE + +hDecoder->element_alloced denotes whether or not we have allocated memory for +usage in terms of the specified channel element. Given that it previously only +had two states (1 meaning allocated, and 0 meaning not allocated), it would not +allocate enough memory for parsing a CPE it if is preceeded by a SCE (and +therefor crash). + +These changes fixes the issue by making sure that we allocate additional memory +if so is necessary, and the set of values for hDecoder->element_alloced[n] is +now: + + 0 = nothing allocated + 1 = allocated enough for SCE + 2 = allocated enough for CPE + +All branches that depend on hDecoder->element_alloced[n] prior to this patch +only checks if the value is, or is not, zero. The added state, 2, is therefor +correctly handled automatically. + +https://github.com/videolan/vlc/blob/master/contrib/src/faad2/faad2-fix-cpe-reconstruction.patch + +Signed-off-by: Baruch Siach +--- +Upstream status: commit f1f8e002622196d + libfaad/specrec.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/libfaad/specrec.c b/libfaad/specrec.c +index 9797d6e79468..0e72207fc9c0 100644 +--- a/libfaad/specrec.c ++++ b/libfaad/specrec.c +@@ -1109,13 +1109,13 @@ uint8_t reconstruct_channel_pair(NeAACDecStruct *hDecoder, ic_stream *ics1, ic_s + #ifdef PROFILE + int64_t count = faad_get_ts(); + #endif +- if (hDecoder->element_alloced[hDecoder->fr_ch_ele] == 0) ++ if (hDecoder->element_alloced[hDecoder->fr_ch_ele] != 2) + { + retval = allocate_channel_pair(hDecoder, cpe->channel, (uint8_t)cpe->paired_channel); + if (retval > 0) + return retval; + +- hDecoder->element_alloced[hDecoder->fr_ch_ele] = 1; ++ hDecoder->element_alloced[hDecoder->fr_ch_ele] = 2; + } + + /* dequantisation and scaling */ +-- +2.20.1 + -- 2.30.2