[PATCH v7 07/28] net: Prepare UDS for security module stacking
Casey Schaufler
casey at schaufler-ca.com
Wed Aug 7 19:43:49 UTC 2019
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.
Reviewed-by: Kees Cook <keescook at chromium.org>
Reviewed-by: John Johansen <john.johansen at canonical.com>
Signed-off-by: Casey Schaufler <casey at 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 313e45a3cac3..dcf20da87d1b 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1280,7 +1280,8 @@ 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);
@@ -1418,7 +1419,9 @@ 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 3426d6dacc45..933492c08b8c 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 82f341e84fae..2a5c868ce135 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 ddb838a1b74c..c50a004a1389 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -143,17 +143,17 @@ 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 fa7ab1334f22..fe76dfa0f2fd 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2120,10 +2120,22 @@ 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);
--
2.20.1
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