eglibc-nativesdk: Fix buffer overrun with a relocated SDK

When ld-linux-*.so.2 is relocated to a path that is longer than the
original fixed location, the dynamic loader will crash in open_path
because it implicitly assumes that max_dirnamelen is a fixed size that
never changes.

The allocated buffer will not be large enough to contain the directory
path string which is larger than the fixed location provided at build
time.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>

2 files changed, 43 insertions, 1 deletions

diff --git a/meta/recipes-core/eglibc/eglibc-2.17/relocatable_sdk_fix_openpath.patch b/meta/recipes-core/eglibc/eglibc-2.17/relocatable_sdk_fix_openpath.patch
new file mode 100644
index 0000000000..f164f8f9ae
--- /dev/null
+++ b/meta/recipes-core/eglibc/eglibc-2.17/relocatable_sdk_fix_openpath.patch
@@ -0,0 +1,41 @@
+Upstream-Status: Inappropriate [SDK specific]
+
+eglibc-nativesdk: Fix buffer overrun with a relocated SDK
+
+When ld-linux-*.so.2 is relocated to a path that is longer than the
+original fixed location, the dynamic loader will crash in open_path
+because it implicitly assumes that max_dirnamelen is a fixed size that
+never changes.
+
+The allocated buffer will not be large enough to contain the directory
+path string which is larger than the fixed location provided at build
+time.
+
+Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
+
+---
+ elf/dl-load.c |   12 ++++++++++++
+ 1 file changed, 12 insertions(+)
+
+--- a/elf/dl-load.c
++++ b/elf/dl-load.c
+@@ -1919,7 +1919,19 @@ open_path (const char *name, size_t name
+        given on the command line when rtld is run directly.  */
+     return -1;
+ 
++  do
++    {
++      struct r_search_path_elem *this_dir = *dirs;
++      if (this_dir->dirnamelen > max_dirnamelen)
++	{
++	  max_dirnamelen = this_dir->dirnamelen;
++	}
++    }
++  while (*++dirs != NULL);
++
+   buf = alloca (max_dirnamelen + max_capstrlen + namelen);
++
++  dirs = sps->dirs;
+   do
+     {
+       struct r_search_path_elem *this_dir = *dirs;
diff --git a/meta/recipes-core/eglibc/eglibc_2.17.bb b/meta/recipes-core/eglibc/eglibc_2.17.bb
index 7bdb267eb1..fb49ac4535 100644
--- a/meta/recipes-core/eglibc/eglibc_2.17.bb
+++ b/meta/recipes-core/eglibc/eglibc_2.17.bb
@@ -1,6 +1,6 @@
 require eglibc.inc
 
-PR = "r2"
+PR = "r3"
 
 DEPENDS += "gperf-native kconfig-frontends-native"
 
@@ -45,6 +45,7 @@ LIC_FILES_CHKSUM = "file://LICENSES;md5=e9a558e243b36d3209f380deb394b213 \
 
 SRC_URI_append_class-nativesdk = " file://ld-search-order.patch \
             file://relocatable_sdk.patch \
+            file://relocatable_sdk_fix_openpath.patch \
             "
 S = "${WORKDIR}/eglibc-${PV}/libc"
 B = "${WORKDIR}/build-${TARGET_SYS}"