[PATCH 1/2] SELinux: Fix lsm_get_self_attr()

From: "Mickaël Salaün" <mic@digikod.net>
To: Casey Schaufler <casey@schaufler-ca.com>,
	John Johansen <john.johansen@canonical.com>,
	Paul Moore <paul@paul-moore.com>
Cc: "Mickaël Salaün" <mic@digikod.net>,
	"James Morris" <jmorris@namei.org>,
	"Serge E . Hallyn" <serge@hallyn.com>,
	linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org, stable@vger.kernel.org
Subject: [PATCH 1/2] SELinux: Fix lsm_get_self_attr()
Date: Fri, 23 Feb 2024 20:05:45 +0100	[thread overview]
Message-ID: <20240223190546.3329966-1-mic@digikod.net> (raw)

selinux_lsm_getattr() may not initialize the value's pointer in some
case.  As for proc_pid_attr_read(), initialize this pointer to NULL in
selinux_getselfattr() to avoid an UAF in the kfree() call.

Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: stable@vger.kernel.org
Fixes: 762c934317e6 ("SELinux: Add selfattr hooks")
Signed-off-by: Mickaël Salaün <mic@digikod.net>
---
 security/selinux/hooks.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index a6bf90ace84c..338b023a8c3e 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6559,7 +6559,7 @@ static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
 			       size_t *size, u32 flags)
 {
 	int rc;
-	char *val;
+	char *val = NULL;
 	int val_len;
 
 	val_len = selinux_lsm_getattr(attr, current, &val);
-- 
2.43.0

