package/libsndfile: fix CVE-2019-3832

It was discovered the fix for CVE-2018-19758 (libsndfile) was not
complete and still allows a read beyond the limits of a buffer in
wav_write_header() function in wav.c. A local attacker may use this flaw
to make the application crash.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

diff --git a/package/libsndfile/0005-wav_write_header-don-t-read-past-the-array-end.patch b/package/libsndfile/0005-wav_write_header-don-t-read-past-the-array-end.patch
new file mode 100644 (file)
index 0000000..e958517
--- /dev/null
+++ b/package/libsndfile/0005-wav_write_header-don-t-read-past-the-array-end.patch
@@ -0,0 +1,33 @@
+From 6d7ce94c020cc720a6b28719d1a7879181790008 Mon Sep 17 00:00:00 2001
+From: Emilio Pozuelo Monfort <pochu27@gmail.com>
+Date: Tue, 5 Mar 2019 11:27:17 +0100
+Subject: [PATCH] wav_write_header: don't read past the array end
+
+If loop_count is bigger than the array, truncate it to the array
+length (and not to 32k).
+
+CVE-2019-3832
+[Retrieved from:
+https://github.com/erikd/libsndfile/commit/6d7ce94c020cc720a6b28719d1a7879181790008]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ src/wav.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/src/wav.c b/src/wav.c
+index 5c825f2a..104bd0a7 100644
+--- a/src/wav.c
++++ b/src/wav.c
+@@ -1146,8 +1146,10 @@ wav_write_header (SF_PRIVATE *psf, int calc_length)
+               psf_binheader_writef (psf, "44", BHW4 (0), BHW4 (0)) ; /* SMTPE format */
+               psf_binheader_writef (psf, "44", BHW4 (psf->instrument->loop_count), BHW4 (0)) ;
+ 
+-              /* Loop count is signed 16 bit number so we limit it range to something sensible. */
+-              psf->instrument->loop_count &= 0x7fff ;
++              /* Make sure we don't read past the loops array end. */
++              if (psf->instrument->loop_count > ARRAY_LEN (psf->instrument->loops))
++                      psf->instrument->loop_count = ARRAY_LEN (psf->instrument->loops) ;
++
+               for (tmp = 0 ; tmp < psf->instrument->loop_count ; tmp++)
+               {       int type ;
+ 

diff --git a/package/libsndfile/libsndfile.mk b/package/libsndfile/libsndfile.mk
index 7be822b87504a2d7b119c78be010ba730b235d21..63d9a521e60403a1c4e5b6e06f234af5c9b0c060 100644 (file)
--- a/package/libsndfile/libsndfile.mk
+++ b/package/libsndfile/libsndfile.mk
@@ -22,6 +22,8 @@ LIBSNDFILE_IGNORE_CVES += \
 LIBSNDFILE_IGNORE_CVES += CVE-2018-13419
 # 0004-src-wav.c-Fix-heap-read-overflow.patch
 LIBSNDFILE_IGNORE_CVES += CVE-2018-19758
+# 0005-wav_write_header-don-t-read-past-the-array-end.patch
+LIBSNDFILE_IGNORE_CVES += CVE-2019-3832
 
 LIBSNDFILE_CONF_OPTS = \
        --disable-sqlite \