From c7bdb545d23026b18be53289fd866d1ac07f5f8c Mon Sep 17 00:00:00 2001 From: Darrel Goeddel Date: Tue, 27 Jun 2006 13:26:11 -0700 Subject: [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 --- security/selinux/hooks.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 28832e689800..b6c378dd4f12 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, -- cgit v1.2.3 From 877ce7c1b3afd69a9b1caeb1b9964c992641f52a Mon Sep 17 00:00:00 2001 From: Catherine Zhang Date: Thu, 29 Jun 2006 12:27:47 -0700 Subject: [AF_UNIX]: Datagram getpeersec This patch implements an API whereby an application can determine the label of its peer's Unix datagram sockets via the auxiliary data mechanism of recvmsg. Patch purpose: This patch enables a security-aware application to retrieve the security context of the peer of a Unix datagram socket. The application can then use this security context to determine the security context for processing on behalf of the peer who sent the packet. Patch design and implementation: The design and implementation is very similar to the UDP case for INET sockets. Basically we build upon the existing Unix domain socket API for retrieving user credentials. Linux offers the API for obtaining user credentials via ancillary messages (i.e., out of band/control messages that are bundled together with a normal message). To retrieve the security context, the application first indicates to the kernel such desire by setting the SO_PASSSEC option via getsockopt. Then the application retrieves the security context using the auxiliary data mechanism. An example server application for Unix datagram socket should look like this: toggle = 1; toggle_len = sizeof(toggle); setsockopt(sockfd, SOL_SOCKET, SO_PASSSEC, &toggle, &toggle_len); recvmsg(sockfd, &msg_hdr, 0); if (msg_hdr.msg_controllen > sizeof(struct cmsghdr)) { cmsg_hdr = CMSG_FIRSTHDR(&msg_hdr); if (cmsg_hdr->cmsg_len <= CMSG_LEN(sizeof(scontext)) && cmsg_hdr->cmsg_level == SOL_SOCKET && cmsg_hdr->cmsg_type == SCM_SECURITY) { memcpy(&scontext, CMSG_DATA(cmsg_hdr), sizeof(scontext)); } } sock_setsockopt is enhanced with a new socket option SOCK_PASSSEC to allow a server socket to receive security context of the peer. Testing: We have tested the patch by setting up Unix datagram client and server applications. We verified that the server can retrieve the security context using the auxiliary data mechanism of recvmsg. Signed-off-by: Catherine Zhang Acked-by: Acked-by: James Morris Signed-off-by: David S. Miller --- security/selinux/hooks.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b6c378dd4f12..b85afcf38527 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -69,6 +69,7 @@ #include #include #include +#include #include "avc.h" #include "objsec.h" @@ -3420,7 +3421,13 @@ out: static int selinux_socket_getpeersec_dgram(struct sk_buff *skb, char **secdata, u32 *seclen) { int err = 0; - u32 peer_sid = selinux_socket_getpeer_dgram(skb); + u32 peer_sid; + + if (skb->sk->sk_family == PF_UNIX) + selinux_get_inode_sid(SOCK_INODE(skb->sk->sk_socket), + &peer_sid); + else + peer_sid = selinux_socket_getpeer_dgram(skb); if (peer_sid == SECSID_NULL) return -EINVAL; @@ -3432,8 +3439,6 @@ static int selinux_socket_getpeersec_dgram(struct sk_buff *skb, char **secdata, return 0; } - - static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) { return sk_alloc_security(sk, family, priority); -- cgit v1.2.3