Commit 222a96b3 authored Sep 23, 2021 by Sebastian Andrzej Siewior Committed by Casey Schaufler Sep 24, 2021

smack: Guard smack_ipv6_lock definition within a SMACK_IPV6_PORT_LABELING block



The mutex smack_ipv6_lock is only used with the SMACK_IPV6_PORT_LABELING
block but its definition is outside of the block. This leads to a
defined-but-not-used warning on PREEMPT_RT.

Moving smack_ipv6_lock down to the block where it is used where it used
raises the question why is smk_ipv6_port_list read if nothing is added
to it.
Turns out, only smk_ipv6_port_check() is using it outside of an ifdef
SMACK_IPV6_PORT_LABELING block. However two of three caller invoke
smk_ipv6_port_check() from a ifdef block and only one is using
__is_defined() macro which requires the function and smk_ipv6_port_list
to be around.

Put the lock and list inside an ifdef SMACK_IPV6_PORT_LABELING block to
avoid the warning regarding unused mutex. Extend the ifdef-block to also
cover smk_ipv6_port_check(). Make smack_socket_connect() use ifdef
instead of __is_defined() to avoid complains about missing function.

Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

parent 0817534f

security/smack/smack_lsm.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -51,8 +51,10 @@
		#define SMK_RECEIVING 1
		#define SMK_SENDING 2

		#ifdef SMACK_IPV6_PORT_LABELING
		static DEFINE_MUTEX(smack_ipv6_lock);
		static LIST_HEAD(smk_ipv6_port_list);
		#endif
		struct kmem_cache *smack_rule_cache;
		int smack_enabled __initdata;

		@@ -2603,7 +2605,6 @@ static void smk_ipv6_port_label(struct socket sock, struct sockaddr address)
		mutex_unlock(&smack_ipv6_lock);
		return;
		}
		#endif

		/**
		* smk_ipv6_port_check - check Smack port access
		@@ -2666,6 +2667,7 @@ static int smk_ipv6_port_check(struct sock sk, struct sockaddr_in6 address,

		return smk_ipv6_check(skp, object, address, act);
		}
		#endif

		/**
		* smack_inode_setsecurity - set smack xattrs
		@@ -2852,8 +2854,9 @@ static int smack_socket_connect(struct socket sock, struct sockaddr sap,
		rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
		SMK_CONNECTING);
		}
		if (__is_defined(SMACK_IPV6_PORT_LABELING))
		#ifdef SMACK_IPV6_PORT_LABELING
		rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
		#endif

		return rc;
		}