elfutils: Security Advisory - CVE-2015-0255

Directory traversal vulnerability in the read_long_names function in
libelf/elf_begin.c in elfutils 0.152 and 0.161 allows remote attackers
to write to arbitrary files to the root directory via a / (slash) in a
crafted archive, as demonstrated using the ar program.

https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-9447

Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 60 insertions, 0 deletions

diff --git a/meta/recipes-devtools/elfutils/elfutils-0.161/0001-libelf-Fix-dir-traversal-vuln-in-ar-extraction.patch b/meta/recipes-devtools/elfutils/elfutils-0.161/0001-libelf-Fix-dir-traversal-vuln-in-ar-extraction.patch
new file mode 100644
index 0000000000..7e4e492c1e
--- /dev/null
+++ b/meta/recipes-devtools/elfutils/elfutils-0.161/0001-libelf-Fix-dir-traversal-vuln-in-ar-extraction.patch
@@ -0,0 +1,59 @@
+From 147018e729e7c22eeabf15b82d26e4bf68a0d18e Mon Sep 17 00:00:00 2001
+From: Alexander Cherepanov <cherepan@mccme.ru>
+Date: Sun, 28 Dec 2014 19:57:19 +0300
+Subject: [PATCH] libelf: Fix dir traversal vuln in ar extraction.
+
+Upstream-Status: Backport
+
+read_long_names terminates names at the first '/' found but then skips
+one character without checking (it's supposed to be '\n'). Hence the
+next name could start with any character including '/'. This leads to
+a directory traversal vulnerability at the time the contents of the
+archive is extracted.
+
+The danger is mitigated by the fact that only one '/' is possible in a
+resulting filename and only in the leading position. Hence only files
+in the root directory can be written via this vuln and only when ar is
+executed as root.
+
+The fix for the vuln is to not skip any characters while looking
+for '/'.
+
+Signed-off-by: Alexander Cherepanov <cherepan@mccme.ru>
+---
+ libelf/ChangeLog   | 5 +++++
+ libelf/elf_begin.c | 5 +----
+ 2 files changed, 6 insertions(+), 4 deletions(-)
+
+diff --git a/libelf/ChangeLog b/libelf/ChangeLog
+index 3b88d03..447c354 100644
+--- a/libelf/ChangeLog
++++ b/libelf/ChangeLog
+@@ -1,3 +1,8 @@
++2014-12-28  Alexander Cherepanov  <cherepan@mccme.ru>
++
++	* elf_begin.c (read_long_names): Don't miss '/' right after
++	another '/'. Fixes a dir traversal vuln in ar extraction.
++
+ 2014-12-18  Ulrich Drepper  <drepper@gmail.com>
+ 
+ 	* Makefile.am: Suppress output of textrel_check command.
+diff --git a/libelf/elf_begin.c b/libelf/elf_begin.c
+index 30abe0b..cd3756c 100644
+--- a/libelf/elf_begin.c
++++ b/libelf/elf_begin.c
+@@ -749,10 +749,7 @@ read_long_names (Elf *elf)
+ 	    }
+ 
+ 	  /* NUL-terminate the string.  */
+-	  *runp = '\0';
+-
+-	  /* Skip the NUL byte and the \012.  */
+-	  runp += 2;
++	  *runp++ = '\0';
+ 
+ 	  /* A sanity check.  Somebody might have generated invalid
+ 	     archive.  */
+-- 
+1.9.1
+
diff --git a/meta/recipes-devtools/elfutils/elfutils_0.161.bb b/meta/recipes-devtools/elfutils/elfutils_0.161.bb
index 0dbe9f95f2..e111b34a8a 100644
--- a/meta/recipes-devtools/elfutils/elfutils_0.161.bb
+++ b/meta/recipes-devtools/elfutils/elfutils_0.161.bb
@@ -16,6 +16,7 @@ SRC_URI += "\
         file://Fix_elf_cvt_gunhash.patch \
         file://fixheadercheck.patch \
         file://0001-elf_getarsym-Silence-Werror-maybe-uninitialized-fals.patch \
+        file://0001-libelf-Fix-dir-traversal-vuln-in-ar-extraction.patch \
 "
 
 # pick the patch from debian