From: Tom Rix <trix@redhat.com>
Date: Wed, 10 Jun 2020 21:57:13 +0000 (-0700)
Subject: selinux: fix double free
X-Git-Tag: v5.7.6~52
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3f58f50d955d5600e56e665d60f455f027c3041;p=thirdparty%2Fkernel%2Fstable.git

selinux: fix double free

commit 65de50969a77509452ae590e9449b70a22b923bb upstream.

Clang's static analysis tool reports these double free memory errors.

security/selinux/ss/services.c:2987:4: warning: Attempt to free released memory [unix.Malloc]
                        kfree(bnames[i]);
                        ^~~~~~~~~~~~~~~~
security/selinux/ss/services.c:2990:2: warning: Attempt to free released memory [unix.Malloc]
        kfree(bvalues);
        ^~~~~~~~~~~~~~

So improve the security_get_bools error handling by freeing these variables
and setting their return pointers to NULL and the return len to 0

Cc: stable@vger.kernel.org
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 8ad34fd031d13..77e591fce9191 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2923,8 +2923,12 @@ err:
 	if (*names) {
 		for (i = 0; i < *len; i++)
 			kfree((*names)[i]);
+		kfree(*names);
 	}
 	kfree(*values);
+	*len = 0;
+	*names = NULL;
+	*values = NULL;
 	goto out;
 }