From: Nathan Chancellor <natechancellor@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Moore <paul@paul-moore.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
Eric Paris <eparis@parisplace.org>,
clang-built-linux@googlegroups.com,
Nick Desaulniers <ndesaulniers@google.com>,
selinux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] selinux: avoid uninitialized variable warning
Date: Fri, 22 Mar 2019 08:17:45 -0700 [thread overview]
Message-ID: <20190322151745.GB13220@archlinux-ryzen> (raw)
In-Reply-To: <20190322141414.496017-1-arnd@arndb.de>
On Fri, Mar 22, 2019 at 03:14:10PM +0100, Arnd Bergmann wrote:
> 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>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> 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
>
next prev parent reply other threads:[~2019-03-22 15:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-22 14:14 [PATCH] selinux: avoid uninitialized variable warning Arnd Bergmann
2019-03-22 15:17 ` Nathan Chancellor [this message]
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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