busybox: CVE-2017-15874

* CVE-2017-15874
busybox: Integer underflow in archival/libarchive/decompress_unlzma.c

(cherry picked from 9ac42c500586fa5f10a1f6d22c3f797df11b1f6b)

Affects busybox <= 1.27.2

CVE: CVE-2017-15874
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-15874
(From OE-Core rev: c35a0355a3561cd17703ece3a66c3389ceb224bf)

Signed-off-by: Sinan Kaya <okaya@kernel.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/busybox/busybox/CVE-2017-15874.patch

@@ -0,0 +1,30 @@
+From e75c01bb3249df16201b482b79bb24bec3b58188 Mon Sep 17 00:00:00 2001
+From: Denys Vlasenko <vda.linux@googlemail.com>
+Date: Fri, 27 Oct 2017 15:37:03 +0200
+Subject: [PATCH] unlzma: fix SEGV, closes 10436
+
+Upstream-Status: Backport [ https://git.busybox.net/busybox/commit/?id=9ac42c500586fa5f10a1f6d22c3f797df11b1f6b]
+Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
+Signed-off-by: Sinan Kaya <okaya@kernel.org>
+---
+ archival/libarchive/decompress_unlzma.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/archival/libarchive/decompress_unlzma.c b/archival/libarchive/decompress_unlzma.c
+index 29eee2a..41e492f 100644
+--- a/archival/libarchive/decompress_unlzma.c
++++ b/archival/libarchive/decompress_unlzma.c
+@@ -353,6 +353,10 @@ unpack_lzma_stream(transformer_state_t *xstate)
+ 						pos = buffer_pos - rep0;
+ 						if ((int32_t)pos < 0) {
+ 							pos += header.dict_size;
++							/* bug 10436 has an example file where this triggers: */
++							if ((int32_t)pos < 0)
++								goto bad;
++
+ 							/* see unzip_bad_lzma_2.zip: */
+ 							if (pos >= buffer_size)
+ 								goto bad;
+-- 
+2.19.0
+

meta/recipes-core/busybox/busybox_1.27.2.bb

@@ -47,6 +47,7 @@ SRC_URI = "http://www.busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \
            file://busybox-CVE-2017-16544.patch \
            file://busybox-fix-lzma-segfaults.patch \
            file://umount-ignore-c.patch \
+           file://CVE-2017-15874.patch \
 "
 SRC_URI_append_libc-musl = " file://musl.cfg "