linux-kernel - [PATCH v2] hooks: fix a missing-check bug in selinux_add_mnt

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190530085438.GA2862@zhanggen-UX430UQ>
Date:   Thu, 30 May 2019 16:54:38 +0800
From:   Gen Zhang <blackgod016574@...il.com>
To:     Ondrej Mosnacek <omosnace@...hat.com>
Cc:     Paul Moore <paul@...l-moore.com>,
        Stephen Smalley <sds@...ho.nsa.gov>,
        Eric Paris <eparis@...isplace.org>, ccross@...roid.com,
        selinux@...r.kernel.org,
        Linux kernel mailing list <linux-kernel@...r.kernel.org>,
        netdev@...r.kernel.org
Subject: [PATCH v2] hooks: fix a missing-check bug in selinux_add_mnt_opt()

In selinux_add_mnt_opt(), 'val' is allcoted by kmemdup_nul(). It returns
NULL when fails. So 'val' should be checked.

Signed-off-by: Gen Zhang <blackgod016574@...il.com>
Fixes: 757cbe597fe8 ("LSM: new method: ->sb_add_mnt_opt()")
---
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3ec702c..4797c63 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1052,8 +1052,11 @@ static int selinux_add_mnt_opt(const char *option, const char *val, int len,
 	if (token == Opt_error)
 		return -EINVAL;
 
-	if (token != Opt_seclabel)
-		val = kmemdup_nul(val, len, GFP_KERNEL);
+	if (token != Opt_seclabel) {
+			val = kmemdup_nul(val, len, GFP_KERNEL);
+			if (!val)
+				return -ENOMEM;
+	}
 	rc = selinux_add_opt(token, val, mnt_opts);
 	if (unlikely(rc)) {
 		kfree(val);