[PATCH v18 18/23] NET: Store LSM netlabel data in a lsmblob
Casey Schaufler
casey at schaufler-ca.com
Thu Jul 9 00:12:29 UTC 2020
Netlabel uses LSM interfaces requiring an lsmblob and
the internal storage is used to pass information between
these interfaces, so change the internal data from a secid
to a lsmblob. Update the netlabel interfaces and their
callers to accommodate the change. This requires that the
modules using netlabel use the lsm_id.slot to access the
correct secid when using netlabel.
Reviewed-by: Kees Cook <keescook at chromium.org>
Reviewed-by: John Johansen <john.johansen at canonical.com>
Acked-by: Stephen Smalley <sds at tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
Cc: netdev at vger.kernel.org
---
include/net/netlabel.h | 8 +--
net/ipv4/cipso_ipv4.c | 27 ++++++----
net/netlabel/netlabel_kapi.c | 6 +--
net/netlabel/netlabel_unlabeled.c | 79 +++++++++--------------------
net/netlabel/netlabel_unlabeled.h | 2 +-
security/selinux/hooks.c | 2 +-
security/selinux/include/security.h | 1 +
security/selinux/netlabel.c | 2 +-
security/selinux/ss/services.c | 4 +-
security/smack/smack.h | 1 +
security/smack/smack_lsm.c | 5 +-
security/smack/smackfs.c | 10 ++--
12 files changed, 65 insertions(+), 82 deletions(-)
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 43ae50337685..73fc25b4042b 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -166,7 +166,7 @@ struct netlbl_lsm_catmap {
* @attr.mls: MLS sensitivity label
* @attr.mls.cat: MLS category bitmap
* @attr.mls.lvl: MLS sensitivity level
- * @attr.secid: LSM specific secid token
+ * @attr.lsmblob: LSM specific data
*
* Description:
* This structure is used to pass security attributes between NetLabel and the
@@ -201,7 +201,7 @@ struct netlbl_lsm_secattr {
struct netlbl_lsm_catmap *cat;
u32 lvl;
} mls;
- u32 secid;
+ struct lsmblob lsmblob;
} attr;
};
@@ -415,7 +415,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info);
int netlbl_cfg_unlbl_static_del(struct net *net,
const char *dev_name,
@@ -523,7 +523,7 @@ static inline int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
return -ENOSYS;
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index a23094b050f8..469baf6704f5 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1;
/* Base length of the local tag (non-standard tag).
* Tag definition (may change between kernel versions)
*
- * 0 8 16 24 32
- * +----------+----------+----------+----------+
- * | 10000000 | 00000110 | 32-bit secid value |
- * +----------+----------+----------+----------+
- * | in (host byte order)|
- * +----------+----------+
- *
+ * 0 8 16 16 + sizeof(struct lsmblob)
+ * +----------+----------+---------------------+
+ * | 10000000 | 00000110 | LSM blob data |
+ * +----------+----------+---------------------+
+ *
+ * All secid and flag fields are in host byte order.
+ * The lsmblob structure size varies depending on which
+ * Linux security modules are built in the kernel.
+ * The data is opaque.
*/
-#define CIPSO_V4_TAG_LOC_BLEN 6
+#define CIPSO_V4_TAG_LOC_BLEN (2 + sizeof(struct lsmblob))
/*
* Helper Functions
@@ -1469,7 +1471,12 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
buffer[0] = CIPSO_V4_TAG_LOCAL;
buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
- *(u32 *)&buffer[2] = secattr->attr.secid;
+ /* Ensure that there is sufficient space in the CIPSO header
+ * for the LSM data. This should never become an issue.
+ * The check is made from an abundance of caution. */
+ BUILD_BUG_ON(CIPSO_V4_TAG_LOC_BLEN > CIPSO_V4_OPT_LEN_MAX);
+ memcpy(&buffer[2], &secattr->attr.lsmblob,
+ sizeof(secattr->attr.lsmblob));
return CIPSO_V4_TAG_LOC_BLEN;
}
@@ -1489,7 +1496,7 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
const unsigned char *tag,
struct netlbl_lsm_secattr *secattr)
{
- secattr->attr.secid = *(u32 *)&tag[2];
+ memcpy(&secattr->attr.lsmblob, &tag[2], sizeof(secattr->attr.lsmblob));
secattr->flags |= NETLBL_SECATTR_SECID;
return 0;
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index 5e1239cef000..bbfaff539416 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -196,7 +196,7 @@ int netlbl_cfg_unlbl_map_add(const char *domain,
* @addr: IP address in network byte order (struct in[6]_addr)
* @mask: address mask in network byte order (struct in[6]_addr)
* @family: address family
- * @secid: LSM secid value for the entry
+ * @lsmblob: LSM data value for the entry
* @audit_info: NetLabel audit information
*
* Description:
@@ -210,7 +210,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
u32 addr_len;
@@ -230,7 +230,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
return netlbl_unlhsh_add(net,
dev_name, addr, mask, addr_len,
- secid, audit_info);
+ lsmblob, audit_info);
}
/**
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index cf4c56beb3ec..c14a485ff045 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -66,7 +66,7 @@ struct netlbl_unlhsh_tbl {
#define netlbl_unlhsh_addr4_entry(iter) \
container_of(iter, struct netlbl_unlhsh_addr4, list)
struct netlbl_unlhsh_addr4 {
- u32 secid;
+ struct lsmblob lsmblob;
struct netlbl_af4list list;
struct rcu_head rcu;
@@ -74,7 +74,7 @@ struct netlbl_unlhsh_addr4 {
#define netlbl_unlhsh_addr6_entry(iter) \
container_of(iter, struct netlbl_unlhsh_addr6, list)
struct netlbl_unlhsh_addr6 {
- u32 secid;
+ struct lsmblob lsmblob;
struct netlbl_af6list list;
struct rcu_head rcu;
@@ -220,7 +220,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
* @iface: the associated interface entry
* @addr: IPv4 address in network byte order
* @mask: IPv4 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
*
* Description:
* Add a new address entry into the unlabeled connection hash table using the
@@ -231,7 +231,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
const struct in_addr *addr,
const struct in_addr *mask,
- u32 secid)
+ struct lsmblob *lsmblob)
{
int ret_val;
struct netlbl_unlhsh_addr4 *entry;
@@ -243,7 +243,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
entry->list.addr = addr->s_addr & mask->s_addr;
entry->list.mask = mask->s_addr;
entry->list.valid = 1;
- entry->secid = secid;
+ entry->lsmblob = *lsmblob;
spin_lock(&netlbl_unlhsh_lock);
ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
@@ -260,7 +260,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
* @iface: the associated interface entry
* @addr: IPv6 address in network byte order
* @mask: IPv6 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
*
* Description:
* Add a new address entry into the unlabeled connection hash table using the
@@ -271,7 +271,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
const struct in6_addr *addr,
const struct in6_addr *mask,
- u32 secid)
+ struct lsmblob *lsmblob)
{
int ret_val;
struct netlbl_unlhsh_addr6 *entry;
@@ -287,7 +287,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
entry->list.mask = *mask;
entry->list.valid = 1;
- entry->secid = secid;
+ entry->lsmblob = *lsmblob;
spin_lock(&netlbl_unlhsh_lock);
ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
@@ -366,7 +366,7 @@ int netlbl_unlhsh_add(struct net *net,
const void *addr,
const void *mask,
u32 addr_len,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
int ret_val;
@@ -375,7 +375,6 @@ int netlbl_unlhsh_add(struct net *net,
struct netlbl_unlhsh_iface *iface;
struct audit_buffer *audit_buf = NULL;
struct lsmcontext context;
- struct lsmblob blob;
if (addr_len != sizeof(struct in_addr) &&
addr_len != sizeof(struct in6_addr))
@@ -408,7 +407,7 @@ int netlbl_unlhsh_add(struct net *net,
const struct in_addr *addr4 = addr;
const struct in_addr *mask4 = mask;
- ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
+ ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, lsmblob);
if (audit_buf != NULL)
netlbl_af4list_audit_addr(audit_buf, 1,
dev_name,
@@ -421,7 +420,7 @@ int netlbl_unlhsh_add(struct net *net,
const struct in6_addr *addr6 = addr;
const struct in6_addr *mask6 = mask;
- ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
+ ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, lsmblob);
if (audit_buf != NULL)
netlbl_af6list_audit_addr(audit_buf, 1,
dev_name,
@@ -438,11 +437,7 @@ int netlbl_unlhsh_add(struct net *net,
unlhsh_add_return:
rcu_read_unlock();
if (audit_buf != NULL) {
- /* lsmblob_init() puts secid into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, secid);
- if (security_secid_to_secctx(&blob, &context) == 0) {
+ if (security_secid_to_secctx(lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -477,7 +472,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -497,13 +491,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
addr->s_addr, mask->s_addr);
if (dev != NULL)
dev_put(dev);
- /* lsmblob_init() puts entry->secid into all of the secids
- * in blob. security_secid_to_secctx() will know which
- * security module to use to create the secctx. */
- if (entry != NULL)
- lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -544,7 +533,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -563,13 +551,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
addr, mask);
if (dev != NULL)
dev_put(dev);
- /* lsmblob_init() puts entry->secid into all of the secids
- * in blob. security_secid_to_secctx() will know which
- * security module to use to create the secctx. */
- if (entry != NULL)
- lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -923,14 +906,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
if (ret_val != 0)
return ret_val;
- /* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
- * instead of a u32 later in this patch set. security_secctx_to_secid()
- * will only be setting one entry in the lsmblob struct, so it is
- * safe to use lsmblob_value() to get that one value. */
-
- return netlbl_unlhsh_add(&init_net,
- dev_name, addr, mask, addr_len,
- lsmblob_value(&blob), &audit_info);
+ return netlbl_unlhsh_add(&init_net, dev_name, addr, mask, addr_len,
+ &blob, &audit_info);
}
/**
@@ -977,11 +954,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
if (ret_val != 0)
return ret_val;
- /* security_secctx_to_secid() will only put one secid into the lsmblob
- * so it's safe to use lsmblob_value() to get the secid. */
- return netlbl_unlhsh_add(&init_net,
- NULL, addr, mask, addr_len,
- lsmblob_value(&blob), &audit_info);
+ return netlbl_unlhsh_add(&init_net, NULL, addr, mask, addr_len, &blob,
+ &audit_info);
}
/**
@@ -1093,8 +1067,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
struct net_device *dev;
struct lsmcontext context;
void *data;
- u32 secid;
- struct lsmblob blob;
+ struct lsmblob *lsmb;
data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1132,7 +1105,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
if (ret_val != 0)
goto list_cb_failure;
- secid = addr4->secid;
+ lsmb = (struct lsmblob *)&addr4->lsmblob;
} else {
ret_val = nla_put_in6_addr(cb_arg->skb,
NLBL_UNLABEL_A_IPV6ADDR,
@@ -1146,14 +1119,10 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
if (ret_val != 0)
goto list_cb_failure;
- secid = addr6->secid;
+ lsmb = (struct lsmblob *)&addr6->lsmblob;
}
- /* lsmblob_init() secid into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, secid);
- ret_val = security_secid_to_secctx(&blob, &context);
+ ret_val = security_secid_to_secctx(lsmb, &context);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
@@ -1505,7 +1474,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
&iface->addr4_list);
if (addr4 == NULL)
goto unlabel_getattr_nolabel;
- secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
+ secattr->attr.lsmblob = netlbl_unlhsh_addr4_entry(addr4)->lsmblob;
break;
}
#if IS_ENABLED(CONFIG_IPV6)
@@ -1518,7 +1487,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
&iface->addr6_list);
if (addr6 == NULL)
goto unlabel_getattr_nolabel;
- secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
+ secattr->attr.lsmblob = netlbl_unlhsh_addr6_entry(addr6)->lsmblob;
break;
}
#endif /* IPv6 */
diff --git a/net/netlabel/netlabel_unlabeled.h b/net/netlabel/netlabel_unlabeled.h
index 058e3a285d56..168920780994 100644
--- a/net/netlabel/netlabel_unlabeled.h
+++ b/net/netlabel/netlabel_unlabeled.h
@@ -211,7 +211,7 @@ int netlbl_unlhsh_add(struct net *net,
const void *addr,
const void *mask,
u32 addr_len,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info);
int netlbl_unlhsh_remove(struct net *net,
const char *dev_name,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index bedcf737ff26..c13c207c5da1 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6940,7 +6940,7 @@ static int selinux_perf_event_write(struct perf_event *event)
}
#endif
-static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+struct lsm_id selinux_lsmid __lsm_ro_after_init = {
.lsm = "selinux",
.slot = LSMBLOB_NEEDED
};
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index b0e02cfe3ce1..cee2987647dd 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -71,6 +71,7 @@
struct netlbl_lsm_secattr;
extern int selinux_enabled_boot;
+extern struct lsm_id selinux_lsmid;
/* Policy capabilities */
enum {
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 6a94b31b5472..d8d7603ab14e 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -108,7 +108,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
return NULL;
if ((secattr->flags & NETLBL_SECATTR_SECID) &&
- (secattr->attr.secid == sid))
+ (secattr->attr.lsmblob.secid[selinux_lsmid.slot] == sid))
return secattr;
return NULL;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index ef0afd878bfc..c59ecf7b61b7 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3637,7 +3637,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
if (secattr->flags & NETLBL_SECATTR_CACHE)
*sid = *(u32 *)secattr->cache->data;
else if (secattr->flags & NETLBL_SECATTR_SECID)
- *sid = secattr->attr.secid;
+ *sid = secattr->attr.lsmblob.secid[selinux_lsmid.slot];
else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
rc = -EIDRM;
ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
@@ -3710,7 +3710,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
if (secattr->domain == NULL)
goto out;
- secattr->attr.secid = sid;
+ secattr->attr.lsmblob.secid[selinux_lsmid.slot] = sid;
secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
mls_export_netlbl_lvl(policydb, ctx, secattr);
rc = mls_export_netlbl_cat(policydb, ctx, secattr);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 7481fa71de19..c284b104e1cc 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -310,6 +310,7 @@ void smk_destroy_label_list(struct list_head *list);
* Shared data.
*/
extern int smack_enabled;
+extern struct lsm_id smack_lsmid;
extern int smack_cipso_direct;
extern int smack_cipso_mapped;
extern struct smack_known *smack_net_ambient;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 8b708cca921a..6f0cdb40addc 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3751,7 +3751,8 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
/*
* Looks like a fallback, which gives us a secid.
*/
- return smack_from_secid(sap->attr.secid);
+ return smack_from_secid(
+ sap->attr.lsmblob.secid[smack_lsmid.slot]);
/*
* Without guidance regarding the smack value
* for the packet fall back on the network
@@ -4656,7 +4657,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
.lbs_sock = sizeof(struct socket_smack),
};
-static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+struct lsm_id smack_lsmid __lsm_ro_after_init = {
.lsm = "smack",
.slot = LSMBLOB_NEEDED
};
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index c21b656b3263..177e69b43a52 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1132,6 +1132,7 @@ static void smk_net4addr_insert(struct smk_net4addr *new)
static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
+ struct lsmblob lsmblob;
struct smk_net4addr *snp;
struct sockaddr_in newname;
char *smack;
@@ -1263,10 +1264,13 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
* this host so that incoming packets get labeled.
* but only if we didn't get the special CIPSO option
*/
- if (rc == 0 && skp != NULL)
+ if (rc == 0 && skp != NULL) {
+ lsmblob_init(&lsmblob, 0);
+ lsmblob.secid[smack_lsmid.slot] = snp->smk_label->smk_secid;
rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
- &snp->smk_host, &snp->smk_mask, PF_INET,
- snp->smk_label->smk_secid, &audit_info);
+ &snp->smk_host, &snp->smk_mask, PF_INET, &lsmblob,
+ &audit_info);
+ }
if (rc == 0)
rc = count;
--
2.24.1
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