Re: [PATCH v19 05/23] net: Prepare UDS for security module stacking

Change the data used in UDS SO_PEERSEC processing from a secid to a more general struct lsmblob. Update the security_socket_getpeersec_dgram() interface to use the lsmblob. There is a small amount of scaffolding code that will come out when the security_secid_to_secctx() code is brought in line with the lsmblob. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt;

--- include/linux/security.h | 7 +++++-- include/net/af_unix.h | 2 +- include/net/scm.h | 8 +++++--- net/ipv4/ip_sockglue.c | 8 +++++--- net/unix/af_unix.c | 6 +++--- security/security.c | 18 +++++++++++++++--- 6 files changed, 34 insertions(+), 15 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 6d403a522918..d81e8886d799 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1397,7 +1397,8 @@ int security_socket_shutdown(struct socket *sock, int how); int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb); int security_socket_getpeersec_stream(struct socket *sock, char __user *optval, int __user *optlen, unsigned len); -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid); +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, + struct lsmblob *blob); int security_sk_alloc(struct sock *sk, int family, gfp_t priority); void security_sk_free(struct sock *sk); void security_sk_clone(const struct sock *sk, struct sock *newsk); @@ -1535,7 +1536,9 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __ return -ENOPROTOOPT; } -static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +static inline int security_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, + struct lsmblob *blob) { return -ENOPROTOOPT; } diff --git a/include/net/af_unix.h b/include/net/af_unix.h index f42fdddecd41..a86da0cb5ec1 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -36,7 +36,7 @@ struct unix_skb_parms { kgid_t gid; struct scm_fp_list *fp; /* Passed files */ #ifdef CONFIG_SECURITY_NETWORK - u32 secid; /* Security ID */ + struct lsmblob lsmblob; /* Security LSM data */ #endif u32 consumed; } __randomize_layout; diff --git a/include/net/scm.h b/include/net/scm.h index 1ce365f4c256..e2e71c4bf9d0 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -33,7 +33,7 @@ struct scm_cookie { struct scm_fp_list *fp; /* Passed files */ struct scm_creds creds; /* Skb credentials */ #ifdef CONFIG_SECURITY_NETWORK - u32 secid; /* Passed security ID */ + struct lsmblob lsmblob; /* Passed LSM data */ #endif }; @@ -46,7 +46,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl); #ifdef CONFIG_SECURITY_NETWORK static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) { - security_socket_getpeersec_dgram(sock, NULL, &scm->secid); + security_socket_getpeersec_dgram(sock, NULL, &scm->lsmblob); } #else static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) @@ -97,7 +97,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc int err; if (test_bit(SOCK_PASSSEC, &sock->flags)) { - err = security_secid_to_secctx(scm->secid, &secdata, &seclen); + /* Scaffolding - it has to be element 0 for now */ + err = security_secid_to_secctx(scm->lsmblob.secid[0], + &secdata, &seclen); if (!err) { put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 84ec3703c909..3ea1103b4c29 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -130,15 +130,17 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) { + struct lsmblob lb; char *secdata; - u32 seclen, secid; + u32 seclen; int err; - err = security_socket_getpeersec_dgram(NULL, skb, &secid); + err = security_socket_getpeersec_dgram(NULL, skb, &lb); if (err) return; - err = security_secid_to_secctx(secid, &secdata, &seclen); + /* Scaffolding - it has to be element 0 */ + err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen); if (err) return; diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 3385a7a0b231..a676dc264464 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -138,17 +138,17 @@ static struct hlist_head *unix_sockets_unbound(void *addr) #ifdef CONFIG_SECURITY_NETWORK static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) { - UNIXCB(skb).secid = scm->secid; + UNIXCB(skb).lsmblob = scm->lsmblob; } static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) { - scm->secid = UNIXCB(skb).secid; + scm->lsmblob = UNIXCB(skb).lsmblob; } static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb) { - return (scm->secid == UNIXCB(skb).secid); + return lsmblob_equal(&scm->lsmblob, &(UNIXCB(skb).lsmblob)); } #else static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) diff --git a/security/security.c b/security/security.c index d6d882b1f7d5..c42873876954 100644 --- a/security/security.c +++ b/security/security.c @@ -2219,10 +2219,22 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval, optval, optlen, len); } -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, + struct lsmblob *blob) { - return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock, - skb, secid); + struct security_hook_list *hp; + int rc = -ENOPROTOOPT; + + hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram, + list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.socket_getpeersec_dgram(sock, skb, + &blob->secid[hp->lsmid->slot]); + if (rc != 0) + break; + } + return rc; } EXPORT_SYMBOL(security_socket_getpeersec_dgram);