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From: Arnd Bergmann <arnd@arndb.de>
To: Paul Moore <paul@paul-moore.com>,
	Stephen Smalley <sds@tycho.nsa.gov>,
	Eric Paris <eparis@parisplace.org>
Cc: clang-built-linux@googlegroups.com,
	Nick Desaulniers <ndesaulniers@google.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Arnd Bergmann <arnd@arndb.de>,
	selinux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] selinux: avoid uninitialized variable warning
Date: Fri, 22 Mar 2019 15:14:10 +0100	[thread overview]
Message-ID: <20190322141414.496017-1-arnd@arndb.de> (raw)

clang correctly points out a code path that would lead
to an uninitialized variable use:

security/selinux/netlabel.c:310:6: error: variable 'addr' is used uninitialized whenever 'if' condition is false
      [-Werror,-Wsometimes-uninitialized]
        if (ip_hdr(skb)->version == 4) {
            ^~~~~~~~~~~~~~~~~~~~~~~~~
security/selinux/netlabel.c:322:40: note: uninitialized use occurs here
        rc = netlbl_conn_setattr(ep->base.sk, addr, &secattr);
                                              ^~~~
security/selinux/netlabel.c:310:2: note: remove the 'if' if its condition is always true
        if (ip_hdr(skb)->version == 4) {
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
security/selinux/netlabel.c:291:23: note: initialize the variable 'addr' to silence this warning
        struct sockaddr *addr;
                             ^
                              = NULL
1 error generated.

This is probably harmless since we should not see ipv6 packets
of CONFIG_IPV6 is disabled, but it's better to rearrange the code
so this cannot happen.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 security/selinux/netlabel.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 186e727b737b..d0e549d4f486 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -288,7 +288,6 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
 	int rc;
 	struct netlbl_lsm_secattr secattr;
 	struct sk_security_struct *sksec = ep->base.sk->sk_security;
-	struct sockaddr *addr;
 	struct sockaddr_in addr4;
 #if IS_ENABLED(CONFIG_IPV6)
 	struct sockaddr_in6 addr6;
@@ -310,16 +309,15 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
 	if (ip_hdr(skb)->version == 4) {
 		addr4.sin_family = AF_INET;
 		addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
-		addr = (struct sockaddr *)&addr4;
+		rc = netlbl_conn_setattr(ep->base.sk, (void*)&addr4, &secattr);
 #if IS_ENABLED(CONFIG_IPV6)
 	} else {
 		addr6.sin6_family = AF_INET6;
 		addr6.sin6_addr = ipv6_hdr(skb)->saddr;
-		addr = (struct sockaddr *)&addr6;
+		rc = netlbl_conn_setattr(ep->base.sk, (void*)&addr6, &secattr);
 #endif
 	}
 
-	rc = netlbl_conn_setattr(ep->base.sk, addr, &secattr);
 	if (rc == 0)
 		sksec->nlbl_state = NLBL_LABELED;
 
-- 
2.20.0


             reply	other threads:[~2019-03-22 14:14 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-22 14:14 Arnd Bergmann [this message]
2019-03-22 15:17 ` Nathan Chancellor
2019-03-22 20:15 ` Paul Moore
2019-03-22 20:35   ` Arnd Bergmann
2019-03-22 21:00     ` Paul Moore

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