Message-ID: <tencent_D6BF2948237359EE0A47338567B88512D106@qq.com>
From:   xkernel.wang@foxmail.com
To:     paul@paul-moore.com, stephen.smalley.work@gmail.com,
        eparis@parisplace.org
Cc:     selinux@vger.kernel.org, linux-kernel@vger.kernel.org,
        Xiaoke Wang <xkernel.wang@foxmail.com>
Subject: [PATCH] selinux: fix a wrong check condition of strcmp()
Date:   Tue, 14 Dec 2021 17:34:43 +0800
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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From: Xiaoke Wang <xkernel.wang@foxmail.com>

strcmp() will return 0 when two strings(s1, s2 for example) are equal.
And if a negative number means s1 < s2. Here seems should use == 0 as
the condition. Otherwise, the value of genfs->fstype can not be
guaranteed.

Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
---
 security/selinux/ss/services.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 759d878..c9f6c3a 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2883,7 +2883,7 @@ static inline int __security_genfs_sid(struct selinux_policy *policy,
 
 	for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
 		cmp = strcmp(fstype, genfs->fstype);
-		if (cmp <= 0)
+		if (cmp == 0)
 			break;
 	}
 
--