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Wed, 25 Sep 2024 13:11:24 -0700 (PDT) Received: from localhost ([70.22.175.108]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6cb0f4c2f51sm19135376d6.31.2024.09.25.13.11.23 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Sep 2024 13:11:23 -0700 (PDT) From: Paul Moore To: selinux@vger.kernel.org Subject: [PATCH 1/2] selinux: streamline selinux_nlmsg_lookup() Date: Wed, 25 Sep 2024 16:11:07 -0400 Message-ID: <20240925201106.16134-3-paul@paul-moore.com> X-Mailer: git-send-email 2.46.1 Precedence: bulk X-Mailing-List: selinux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4491; i=paul@paul-moore.com; h=from:subject; bh=bRCaExXn9SJy78GX6WWTPKudwEh0moYHW8c3sqQDsV0=; b=owEBbQKS/ZANAwAIAeog8tqXN4lzAcsmYgBm9G5a3e6LIVkkyYpFKpY+rLQdpHZl2t8K9gIuH aVcovpHkJiJAjMEAAEIAB0WIQRLQqjPB/KZ1VSXfu/qIPLalzeJcwUCZvRuWgAKCRDqIPLalzeJ cxPzD/0f5mVGBWvo+cTx+V8HrZxjF/P98q6IR88PFyZLvZPmRf//unFXupfh/0PbeOIZKXHX8YR HsznyD3mJkGIS4Dk4LvarzVhOPXtUbJyqrfGCIDwa1nrNChuQ/9mPHtoRe4EkzgSuaUiE5htk7k /Ar97IYTNM9kH3bOhTFpqh/G/zXsoseLWqkkyRHOz9Mo40iqWDfhBa0XWWWlO1+U64t/NIUTxlR 5JjHj9om7KSI0DW+4KIzl8+T1MHNwf18KOpip4VZD/YUHZY/MZ5aSElGkzv8VBt5jVGxMREnL9e K3xjk+5xgA0mw7AbKCNoEShVxr0/pVsAjgyoV9PIPrbf1D7KykoBGiCstEiZkOi/75k58LozGp5 qBXFvgoSGI7eenDMN23gzzoVZPvzClSVzM8nftWNtt0ovuTNr3EDaTKh70FXiWkvL8kMQeL0OeI pwoJ3Q8XP9NFQiGg7970vaBCO3siMc34x9Xqcwbe4FxUNtq9pxUOLn+MeoDGp6wQ7Ma0OeQ8RfI GfJUzI9+dWE79amOFCGm5O3qJSSfqIBD0brMRilbEr9RgpWSIEkJI6xyxgQbBNQm+OMdvOXhdpR gzDiC1VNlUtnH3zuW4TSSFm12WQKPSwOf2o0caBJbkD0+BMOQmZNMPSUIOt6C0NSPRvLDUc2E97 OOiBAhIimKEcAtA== X-Developer-Key: i=paul@paul-moore.com; a=openpgp; fpr=7100AADFAE6E6E940D2E0AD655E45A5AE8CA7C8A Streamline the code in selinux_nlmsg_lookup() to improve the code flow, readability, and remove the unnecessary local variables. Signed-off-by: Paul Moore Tested-by: Thiébaud Weksteen --- security/selinux/nlmsgtab.c | 90 ++++++++++++++++--------------------- 1 file changed, 39 insertions(+), 51 deletions(-) diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c index acc7d74b99d5..f68b4f493de6 100644 --- a/security/selinux/nlmsgtab.c +++ b/security/selinux/nlmsgtab.c @@ -168,34 +168,12 @@ static int nlmsg_perm(u16 nlmsg_type, u32 *perm, const struct nlmsg_perm *tab, s int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm) { - int err = 0; - - if (selinux_policycap_netlink_xperm()) { - switch (sclass) { - case SECCLASS_NETLINK_ROUTE_SOCKET: - *perm = NETLINK_ROUTE_SOCKET__NLMSG; - break; - case SECCLASS_NETLINK_TCPDIAG_SOCKET: - *perm = NETLINK_TCPDIAG_SOCKET__NLMSG; - break; - case SECCLASS_NETLINK_XFRM_SOCKET: - *perm = NETLINK_XFRM_SOCKET__NLMSG; - break; - case SECCLASS_NETLINK_AUDIT_SOCKET: - *perm = NETLINK_AUDIT_SOCKET__NLMSG; - break; - /* While it is possible to add a similar permission to other - * netlink classes, note that the extended permission value is - * matched against the nlmsg_type field. Notably, - * SECCLASS_NETLINK_GENERIC_SOCKET uses dynamic values for this - * field, which means that it cannot be added as-is. - */ - default: - err = -ENOENT; - break; - } - return err; - } + /* While it is possible to add a similar permission to other netlink + * classes, note that the extended permission value is matched against + * the nlmsg_type field. Notably, SECCLASS_NETLINK_GENERIC_SOCKET uses + * dynamic values for this field, which means that it cannot be added + * as-is. + */ switch (sclass) { case SECCLASS_NETLINK_ROUTE_SOCKET: @@ -205,42 +183,52 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm) * before updating the BUILD_BUG_ON() macro! */ BUILD_BUG_ON(RTM_MAX != (RTM_NEWTUNNEL + 3)); - err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms, - sizeof(nlmsg_route_perms)); - break; + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_ROUTE_SOCKET__NLMSG; + return 0; + } + return nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms, + sizeof(nlmsg_route_perms)); + break; case SECCLASS_NETLINK_TCPDIAG_SOCKET: - err = nlmsg_perm(nlmsg_type, perm, nlmsg_tcpdiag_perms, - sizeof(nlmsg_tcpdiag_perms)); + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_TCPDIAG_SOCKET__NLMSG; + return 0; + } + return nlmsg_perm(nlmsg_type, perm, nlmsg_tcpdiag_perms, + sizeof(nlmsg_tcpdiag_perms)); break; - case SECCLASS_NETLINK_XFRM_SOCKET: /* If the BUILD_BUG_ON() below fails you must update the * structures at the top of this file with the new mappings * before updating the BUILD_BUG_ON() macro! */ BUILD_BUG_ON(XFRM_MSG_MAX != XFRM_MSG_GETDEFAULT); - err = nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms, - sizeof(nlmsg_xfrm_perms)); - break; - case SECCLASS_NETLINK_AUDIT_SOCKET: - if ((nlmsg_type >= AUDIT_FIRST_USER_MSG && - nlmsg_type <= AUDIT_LAST_USER_MSG) || - (nlmsg_type >= AUDIT_FIRST_USER_MSG2 && - nlmsg_type <= AUDIT_LAST_USER_MSG2)) { - *perm = NETLINK_AUDIT_SOCKET__NLMSG_RELAY; - } else { - err = nlmsg_perm(nlmsg_type, perm, nlmsg_audit_perms, - sizeof(nlmsg_audit_perms)); + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_XFRM_SOCKET__NLMSG; + return 0; } + return nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms, + sizeof(nlmsg_xfrm_perms)); break; - - /* No messaging from userspace, or class unknown/unhandled */ - default: - err = -ENOENT; + case SECCLASS_NETLINK_AUDIT_SOCKET: + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_XFRM_SOCKET__NLMSG; + return 0; + } else if ((nlmsg_type >= AUDIT_FIRST_USER_MSG && + nlmsg_type <= AUDIT_LAST_USER_MSG) || + (nlmsg_type >= AUDIT_FIRST_USER_MSG2 && + nlmsg_type <= AUDIT_LAST_USER_MSG2)) { + *perm = NETLINK_AUDIT_SOCKET__NLMSG_RELAY; + return 0; + } + return nlmsg_perm(nlmsg_type, perm, nlmsg_audit_perms, + sizeof(nlmsg_audit_perms)); break; } - return err; + /* No messaging from userspace, or class unknown/unhandled */ + return -ENOENT; }