libselinux: Backport NULL pointer fix from 3.1

Using function restorecon_init inside selinux_restorecon.c can
result in a NULL pointer. This happens because function
selinux_restorecon_set_sehandle can return a NULL pointer. But
it is not checked and directly given to the next function.

This problem is already fixed in libselinux 3.1 and above.
Therefore backport this fix.

Upstream-Status: Backport [https://github.com/SELinuxProject/selinux/commit/08f5e30177218fae7ce9f5c8d6856690126b2b30]
Issue: MGURSU-7259
Change-Id: Ice5c7c94987441ba53431aeffc200c0b9c5697a4
Signed-off-by: Joe MacDonald <joe@deserted.net>

2 files changed, 31 insertions, 0 deletions

diff --git a/recipes-security/selinux/libselinux/0001-Fix-NULL-pointer-use-in-selinux_restorecon_set_sehandle.patch b/recipes-security/selinux/libselinux/0001-Fix-NULL-pointer-use-in-selinux_restorecon_set_sehandle.patch
new file mode 100644
index 0000000..8a9fb7c
--- /dev/null
+++ b/recipes-security/selinux/libselinux/0001-Fix-NULL-pointer-use-in-selinux_restorecon_set_sehandle.patch
@@ -0,0 +1,30 @@
+From 08f5e30177218fae7ce9f5c8d6856690126b2b30 Mon Sep 17 00:00:00 2001
+From: Ji Qin <jiqin.ji@huawei.com>
+Date: Sun, 14 Jun 2020 21:20:23 -0400
+Subject: [PATCH] libselinux: Fix NULL pointer use in
+ selinux_restorecon_set_sehandle
+
+error occur when selinux_restorecon_default_handle return NULL in
+restorecon_init.
+
+fixes: https://github.com/SELinuxProject/selinux/issues/249
+
+Signed-off-by: Ji Qin <jiqin.ji@huawei.com>
+Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
+---
+ libselinux/src/selinux_restorecon.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/libselinux/src/selinux_restorecon.c b/libselinux/src/selinux_restorecon.c
+index d1ce830c5..6993be6fd 100644
+--- a/libselinux/src/selinux_restorecon.c
++++ b/libselinux/src/selinux_restorecon.c
+@@ -1154,6 +1154,8 @@ void selinux_restorecon_set_sehandle(struct selabel_handle *hndl)
+        size_t num_specfiles, fc_digest_len;
+ 
+        fc_sehandle = (struct selabel_handle *) hndl;
++       if (!fc_sehandle)
++               return;
+ 
+        /* Check if digest requested in selabel_open(3), if so use it. */
+        if (selabel_digest(fc_sehandle, &fc_digest, &fc_digest_len,
diff --git a/recipes-security/selinux/libselinux_3.0.bb b/recipes-security/selinux/libselinux_3.0.bb
index 05d2346..4a60962 100644
--- a/recipes-security/selinux/libselinux_3.0.bb
+++ b/recipes-security/selinux/libselinux_3.0.bb
@@ -12,4 +12,5 @@ SRC_URI += "\
         file://libselinux-make-SOCK_CLOEXEC-optional.patch \
         file://libselinux-define-FD_CLOEXEC-as-necessary.patch \
         file://0001-Fix-building-against-musl-and-uClibc-libc-libraries.patch \
+        file://0001-Fix-NULL-pointer-use-in-selinux_restorecon_set_sehandle.patch \
         "