From c7bdb545d23026b18be53289fd866d1ac07f5f8c Mon Sep 17 00:00:00 2001 From: Darrel Goeddel Date: Tue, 27 Jun 2006 13:26:11 -0700 Subject: [PATCH] [NETLINK]: Encapsulate eff_cap usage within security framework. This patch encapsulates the usage of eff_cap (in netlink_skb_params) within the security framework by extending security_netlink_recv to include a required capability parameter and converting all direct usage of eff_caps outside of the lsm modules to use the interface. It also updates the SELinux implementation of the security_netlink_send and security_netlink_recv hooks to take advantage of the sid in the netlink_skb_params struct. This also enables SELinux to perform auditing of netlink capability checks. Please apply, for 2.6.18 if possible. Signed-off-by: Darrel Goeddel Signed-off-by: Stephen Smalley Acked-by: James Morris Signed-off-by: David S. Miller --- include/linux/security.h | 13 +++++++------ kernel/audit.c | 8 ++++---- net/core/rtnetlink.c | 2 +- net/decnet/netfilter/dn_rtmsg.c | 2 +- net/ipv4/netfilter/ip_queue.c | 2 +- net/ipv6/netfilter/ip6_queue.c | 2 +- net/netfilter/nfnetlink.c | 2 +- net/netlink/genetlink.c | 2 +- net/xfrm/xfrm_user.c | 2 +- security/commoncap.c | 4 ++-- security/dummy.c | 4 ++-- security/selinux/hooks.c | 26 +++++++++++++------------- 12 files changed, 35 insertions(+), 34 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 5180580..c7ea157 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -67,7 +67,7 @@ struct xfrm_state; struct xfrm_user_sec_ctx; extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb); -extern int cap_netlink_recv(struct sk_buff *skb); +extern int cap_netlink_recv(struct sk_buff *skb, int cap); /* * Values used in the task_security_ops calls @@ -656,6 +656,7 @@ struct swap_info_struct; * Check permission before processing the received netlink message in * @skb. * @skb contains the sk_buff structure for the netlink message. + * @cap indicates the capability required * Return 0 if permission is granted. * * Security hooks for Unix domain networking. @@ -1266,7 +1267,7 @@ struct security_operations { struct sembuf * sops, unsigned nsops, int alter); int (*netlink_send) (struct sock * sk, struct sk_buff * skb); - int (*netlink_recv) (struct sk_buff * skb); + int (*netlink_recv) (struct sk_buff * skb, int cap); /* allow module stacking */ int (*register_security) (const char *name, @@ -2032,9 +2033,9 @@ static inline int security_netlink_send(struct sock *sk, struct sk_buff * skb) return security_ops->netlink_send(sk, skb); } -static inline int security_netlink_recv(struct sk_buff * skb) +static inline int security_netlink_recv(struct sk_buff * skb, int cap) { - return security_ops->netlink_recv(skb); + return security_ops->netlink_recv(skb, cap); } /* prototypes */ @@ -2670,9 +2671,9 @@ static inline int security_netlink_send (struct sock *sk, struct sk_buff *skb) return cap_netlink_send (sk, skb); } -static inline int security_netlink_recv (struct sk_buff *skb) +static inline int security_netlink_recv (struct sk_buff *skb, int cap) { - return cap_netlink_recv (skb); + return cap_netlink_recv (skb, cap); } static inline struct dentry *securityfs_create_dir(const char *name, diff --git a/kernel/audit.c b/kernel/audit.c index 82443fb..d417ca1 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -445,7 +445,7 @@ void audit_send_reply(int pid, int seq, int type, int done, int multi, * Check for appropriate CAP_AUDIT_ capabilities on incoming audit * control messages. */ -static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type) +static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) { int err = 0; @@ -459,13 +459,13 @@ static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type) case AUDIT_DEL: case AUDIT_DEL_RULE: case AUDIT_SIGNAL_INFO: - if (!cap_raised(eff_cap, CAP_AUDIT_CONTROL)) + if (security_netlink_recv(skb, CAP_AUDIT_CONTROL)) err = -EPERM; break; case AUDIT_USER: case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG: case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2: - if (!cap_raised(eff_cap, CAP_AUDIT_WRITE)) + if (security_netlink_recv(skb, CAP_AUDIT_WRITE)) err = -EPERM; break; default: /* bad msg */ @@ -488,7 +488,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) char *ctx; u32 len; - err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type); + err = audit_netlink_ok(skb, msg_type); if (err) return err; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 3fcfa9c..f25aac1 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -663,7 +663,7 @@ rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp) sz_idx = type>>2; kind = type&3; - if (kind != 2 && security_netlink_recv(skb)) { + if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN)) { *errp = -EPERM; return -1; } diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c index 74133ec..8b99bd3 100644 --- a/net/decnet/netfilter/dn_rtmsg.c +++ b/net/decnet/netfilter/dn_rtmsg.c @@ -107,7 +107,7 @@ static inline void dnrmg_receive_user_skb(struct sk_buff *skb) if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) return; - if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) + if (security_netlink_recv(skb, CAP_NET_ADMIN)) RCV_SKB_FAIL(-EPERM); /* Eventually we might send routing messages too */ diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c index 213d116..198ac36 100644 --- a/net/ipv4/netfilter/ip_queue.c +++ b/net/ipv4/netfilter/ip_queue.c @@ -515,7 +515,7 @@ ipq_rcv_skb(struct sk_buff *skb) if (type <= IPQM_BASE) return; - if (security_netlink_recv(skb)) + if (security_netlink_recv(skb, CAP_NET_ADMIN)) RCV_SKB_FAIL(-EPERM); write_lock_bh(&queue_lock); diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c index b4b7d44..968a14b 100644 --- a/net/ipv6/netfilter/ip6_queue.c +++ b/net/ipv6/netfilter/ip6_queue.c @@ -505,7 +505,7 @@ ipq_rcv_skb(struct sk_buff *skb) if (type <= IPQM_BASE) return; - if (security_netlink_recv(skb)) + if (security_netlink_recv(skb, CAP_NET_ADMIN)) RCV_SKB_FAIL(-EPERM); write_lock_bh(&queue_lock); diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index b88e82a..ec9f0ef 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -229,7 +229,7 @@ static int nfnetlink_rcv_msg(struct sk_buff *skb, NFNL_SUBSYS_ID(nlh->nlmsg_type), NFNL_MSG_TYPE(nlh->nlmsg_type)); - if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) { + if (security_netlink_recv(skb, CAP_NET_ADMIN)) { DEBUGP("missing CAP_NET_ADMIN\n"); *errp = -EPERM; return -1; diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index f329b72..edf084b 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -320,7 +320,7 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, goto errout; } - if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb)) { + if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb, CAP_NET_ADMIN)) { err = -EPERM; goto errout; } diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index c21dc26..3e6a722 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1435,7 +1435,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *err link = &xfrm_dispatch[type]; /* All operations require privileges, even GET */ - if (security_netlink_recv(skb)) { + if (security_netlink_recv(skb, CAP_NET_ADMIN)) { *errp = -EPERM; return -1; } diff --git a/security/commoncap.c b/security/commoncap.c index 841eb4e..57673ee 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -33,9 +33,9 @@ int cap_netlink_send(struct sock *sk, struct sk_buff *skb) EXPORT_SYMBOL(cap_netlink_send); -int cap_netlink_recv(struct sk_buff *skb) +int cap_netlink_recv(struct sk_buff *skb, int cap) { - if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) + if (!cap_raised(NETLINK_CB(skb).eff_cap, cap)) return -EPERM; return 0; } diff --git a/security/dummy.c b/security/dummy.c index 310fcdf..9135408 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -675,9 +675,9 @@ static int dummy_netlink_send (struct sock *sk, struct sk_buff *skb) return 0; } -static int dummy_netlink_recv (struct sk_buff *skb) +static int dummy_netlink_recv (struct sk_buff *skb, int cap) { - if (!cap_raised (NETLINK_CB (skb).eff_cap, CAP_NET_ADMIN)) + if (!cap_raised (NETLINK_CB (skb).eff_cap, cap)) return -EPERM; return 0; } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 28832e6..b6c378d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3641,32 +3641,32 @@ static unsigned int selinux_ipv6_postroute_last(unsigned int hooknum, static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) { - struct task_security_struct *tsec; - struct av_decision avd; int err; err = secondary_ops->netlink_send(sk, skb); if (err) return err; - tsec = current->security; - - avd.allowed = 0; - avc_has_perm_noaudit(tsec->sid, tsec->sid, - SECCLASS_CAPABILITY, ~0, &avd); - cap_mask(NETLINK_CB(skb).eff_cap, avd.allowed); - if (policydb_loaded_version >= POLICYDB_VERSION_NLCLASS) err = selinux_nlmsg_perm(sk, skb); return err; } -static int selinux_netlink_recv(struct sk_buff *skb) +static int selinux_netlink_recv(struct sk_buff *skb, int capability) { - if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) - return -EPERM; - return 0; + int err; + struct avc_audit_data ad; + + err = secondary_ops->netlink_recv(skb, capability); + if (err) + return err; + + AVC_AUDIT_DATA_INIT(&ad, CAP); + ad.u.cap = capability; + + return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid, + SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad); } static int ipc_alloc_security(struct task_struct *task, -- 1.8.2.3