[PATCH v20 05/23] net: Prepare UDS for security module stacking
From: Casey Schaufler <casey@schaufler-ca.com>
Date: 2020-08-26 15:07:10
Also in:
selinux
Subsystem:
networking [general], networking [ipv4/ipv6], networking [unix sockets], security subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Kuniyuki Iwashima, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
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@schaufler-ca.com> --- 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 e2ef982b3dd7..ae623b89cdf4 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h@@ -1398,7 +1398,8 @@ 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);
@@ -1536,7 +1537,9 @@ 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 d2c223554ff7..551dfbc717e9 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 181ea6fb56a6..c15668b80d1d 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);
--
2.24.1