atomic_t selinux_xfrm_refcount = ATOMIC_INIT(0);
/*
- * Returns true if an LSM/SELinux context
+ * Returns true if the context is an LSM/SELinux context.
*/
static inline int selinux_authorizable_ctx(struct xfrm_sec_ctx *ctx)
{
}
/*
- * Returns true if the xfrm contains a security blob for SELinux
+ * Returns true if the xfrm contains a security blob for SELinux.
*/
static inline int selinux_authorizable_xfrm(struct xfrm_state *x)
{
}
/*
- * LSM hook implementation that authorizes that a flow can use
- * a xfrm policy rule.
+ * Allocates a xfrm_sec_state and populates it using the supplied security
+ * xfrm_user_sec_ctx context.
*/
-int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir)
+static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp,
+ struct xfrm_user_sec_ctx *uctx)
{
int rc;
- u32 sel_sid;
+ const struct task_security_struct *tsec = current_security();
+ struct xfrm_sec_ctx *ctx = NULL;
+ u32 str_len;
- /* Context sid is either set to label or ANY_ASSOC */
- if (ctx) {
- if (!selinux_authorizable_ctx(ctx))
- return -EINVAL;
-
- sel_sid = ctx->ctx_sid;
- } else
- /*
- * All flows should be treated as polmatch'ing an
- * otherwise applicable "non-labeled" policy. This
- * would prevent inadvertent "leaks".
- */
- return 0;
+ if (ctxp == NULL || uctx == NULL ||
+ uctx->ctx_doi != XFRM_SC_DOI_LSM ||
+ uctx->ctx_alg != XFRM_SC_ALG_SELINUX)
+ return -EINVAL;
- rc = avc_has_perm(fl_secid, sel_sid, SECCLASS_ASSOCIATION,
- ASSOCIATION__POLMATCH,
- NULL);
+ str_len = uctx->ctx_len;
+ if (str_len >= PAGE_SIZE)
+ return -ENOMEM;
- if (rc == -EACCES)
- return -ESRCH;
+ ctx = kmalloc(sizeof(*ctx) + str_len + 1, GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+ ctx->ctx_doi = XFRM_SC_DOI_LSM;
+ ctx->ctx_alg = XFRM_SC_ALG_SELINUX;
+ ctx->ctx_len = str_len;
+ memcpy(ctx->ctx_str, &uctx[1], str_len);
+ ctx->ctx_str[str_len] = '\0';
+ rc = security_context_to_sid(ctx->ctx_str, str_len, &ctx->ctx_sid);
+ if (rc)
+ goto err;
+
+ rc = avc_has_perm(tsec->sid, ctx->ctx_sid,
+ SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL);
+ if (rc)
+ goto err;
+
+ *ctxp = ctx;
+ atomic_inc(&selinux_xfrm_refcount);
+ return 0;
+
+err:
+ kfree(ctx);
return rc;
}
+/*
+ * Free the xfrm_sec_ctx structure.
+ */
+static void selinux_xfrm_free(struct xfrm_sec_ctx *ctx)
+{
+ if (!ctx)
+ return;
+
+ atomic_dec(&selinux_xfrm_refcount);
+ kfree(ctx);
+}
+
+/*
+ * Authorize the deletion of a labeled SA or policy rule.
+ */
+static int selinux_xfrm_delete(struct xfrm_sec_ctx *ctx)
+{
+ const struct task_security_struct *tsec = current_security();
+
+ if (!ctx)
+ return 0;
+
+ return avc_has_perm(tsec->sid, ctx->ctx_sid,
+ SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
+ NULL);
+}
+
+/*
+ * LSM hook implementation that authorizes that a flow can use a xfrm policy
+ * rule.
+ */
+int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir)
+{
+ int rc;
+
+ /* All flows should be treated as polmatch'ing an otherwise applicable
+ * "non-labeled" policy. This would prevent inadvertent "leaks". */
+ if (!ctx)
+ return 0;
+
+ /* Context sid is either set to label or ANY_ASSOC */
+ if (!selinux_authorizable_ctx(ctx))
+ return -EINVAL;
+
+ rc = avc_has_perm(fl_secid, ctx->ctx_sid,
+ SECCLASS_ASSOCIATION, ASSOCIATION__POLMATCH, NULL);
+ return (rc == -EACCES ? -ESRCH : rc);
+}
+
/*
* LSM hook implementation that authorizes that a state matches
* the given policy, flow combo.
*/
-
-int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *xp,
- const struct flowi *fl)
+int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x,
+ struct xfrm_policy *xp,
+ const struct flowi *fl)
{
u32 state_sid;
- int rc;
if (!xp->security)
if (x->security)
if (fl->flowi_secid != state_sid)
return 0;
- rc = avc_has_perm(fl->flowi_secid, state_sid, SECCLASS_ASSOCIATION,
- ASSOCIATION__SENDTO,
- NULL)? 0:1;
-
- /*
- * We don't need a separate SA Vs. policy polmatch check
- * since the SA is now of the same label as the flow and
- * a flow Vs. policy polmatch check had already happened
- * in selinux_xfrm_policy_lookup() above.
- */
-
- return rc;
+ /* We don't need a separate SA Vs. policy polmatch check since the SA
+ * is now of the same label as the flow and a flow Vs. policy polmatch
+ * check had already happened in selinux_xfrm_policy_lookup() above. */
+ return (avc_has_perm(fl->flowi_secid, state_sid,
+ SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO,
+ NULL) ? 0 : 1);
}
/*
* LSM hook implementation that checks and/or returns the xfrm sid for the
* incoming packet.
*/
-
int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
{
+ u32 sid_session = SECSID_NULL;
struct sec_path *sp;
- *sid = SECSID_NULL;
-
if (skb == NULL)
- return 0;
+ goto out;
sp = skb->sp;
if (sp) {
- int i, sid_set = 0;
+ int i;
- for (i = sp->len-1; i >= 0; i--) {
+ for (i = sp->len - 1; i >= 0; i--) {
struct xfrm_state *x = sp->xvec[i];
if (selinux_authorizable_xfrm(x)) {
struct xfrm_sec_ctx *ctx = x->security;
- if (!sid_set) {
- *sid = ctx->ctx_sid;
- sid_set = 1;
-
+ if (sid_session == SECSID_NULL) {
+ sid_session = ctx->ctx_sid;
if (!ckall)
- break;
- } else if (*sid != ctx->ctx_sid)
+ goto out;
+ } else if (sid_session != ctx->ctx_sid) {
+ *sid = SECSID_NULL;
return -EINVAL;
+ }
}
}
}
- return 0;
-}
-
-/*
- * Security blob allocation for xfrm_policy and xfrm_state
- * CTX does not have a meaningful value on input
- */
-static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp,
- struct xfrm_user_sec_ctx *uctx, u32 sid)
-{
- int rc = 0;
- const struct task_security_struct *tsec = current_security();
- struct xfrm_sec_ctx *ctx = NULL;
- char *ctx_str = NULL;
- u32 str_len;
-
- BUG_ON(uctx && sid);
-
- if (!uctx)
- goto not_from_user;
-
- if (uctx->ctx_alg != XFRM_SC_ALG_SELINUX)
- return -EINVAL;
-
- str_len = uctx->ctx_len;
- if (str_len >= PAGE_SIZE)
- return -ENOMEM;
-
- *ctxp = ctx = kmalloc(sizeof(*ctx) +
- str_len + 1,
- GFP_KERNEL);
-
- if (!ctx)
- return -ENOMEM;
-
- ctx->ctx_doi = uctx->ctx_doi;
- ctx->ctx_len = str_len;
- ctx->ctx_alg = uctx->ctx_alg;
-
- memcpy(ctx->ctx_str,
- uctx+1,
- str_len);
- ctx->ctx_str[str_len] = 0;
- rc = security_context_to_sid(ctx->ctx_str,
- str_len,
- &ctx->ctx_sid);
-
- if (rc)
- goto out;
-
- /*
- * Does the subject have permission to set security context?
- */
- rc = avc_has_perm(tsec->sid, ctx->ctx_sid,
- SECCLASS_ASSOCIATION,
- ASSOCIATION__SETCONTEXT, NULL);
- if (rc)
- goto out;
-
- return rc;
-
-not_from_user:
- rc = security_sid_to_context(sid, &ctx_str, &str_len);
- if (rc)
- goto out;
-
- *ctxp = ctx = kmalloc(sizeof(*ctx) +
- str_len,
- GFP_ATOMIC);
-
- if (!ctx) {
- rc = -ENOMEM;
- goto out;
- }
-
- ctx->ctx_doi = XFRM_SC_DOI_LSM;
- ctx->ctx_alg = XFRM_SC_ALG_SELINUX;
- ctx->ctx_sid = sid;
- ctx->ctx_len = str_len;
- memcpy(ctx->ctx_str,
- ctx_str,
- str_len);
-
- goto out2;
-
out:
- *ctxp = NULL;
- kfree(ctx);
-out2:
- kfree(ctx_str);
- return rc;
+ *sid = sid_session;
+ return 0;
}
/*
- * LSM hook implementation that allocs and transfers uctx spec to
- * xfrm_policy.
+ * LSM hook implementation that allocs and transfers uctx spec to xfrm_policy.
*/
int selinux_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp,
struct xfrm_user_sec_ctx *uctx)
{
- int err;
-
- BUG_ON(!uctx);
-
- err = selinux_xfrm_sec_ctx_alloc(ctxp, uctx, 0);
- if (err == 0)
- atomic_inc(&selinux_xfrm_refcount);
-
- return err;
+ return selinux_xfrm_alloc_user(ctxp, uctx);
}
-
/*
- * LSM hook implementation that copies security data structure from old to
- * new for policy cloning.
+ * LSM hook implementation that copies security data structure from old to new
+ * for policy cloning.
*/
int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx,
struct xfrm_sec_ctx **new_ctxp)
{
struct xfrm_sec_ctx *new_ctx;
- if (old_ctx) {
- new_ctx = kmalloc(sizeof(*old_ctx) + old_ctx->ctx_len,
- GFP_ATOMIC);
- if (!new_ctx)
- return -ENOMEM;
+ if (!old_ctx)
+ return 0;
+
+ new_ctx = kmemdup(old_ctx, sizeof(*old_ctx) + old_ctx->ctx_len,
+ GFP_ATOMIC);
+ if (!new_ctx)
+ return -ENOMEM;
+ atomic_inc(&selinux_xfrm_refcount);
+ *new_ctxp = new_ctx;
- memcpy(new_ctx, old_ctx, sizeof(*new_ctx));
- memcpy(new_ctx->ctx_str, old_ctx->ctx_str, new_ctx->ctx_len);
- atomic_inc(&selinux_xfrm_refcount);
- *new_ctxp = new_ctx;
- }
return 0;
}
*/
void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx)
{
- atomic_dec(&selinux_xfrm_refcount);
- kfree(ctx);
+ selinux_xfrm_free(ctx);
}
/*
*/
int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx)
{
- const struct task_security_struct *tsec = current_security();
-
- if (!ctx)
- return 0;
+ return selinux_xfrm_delete(ctx);
+}
- return avc_has_perm(tsec->sid, ctx->ctx_sid,
- SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
- NULL);
+/*
+ * LSM hook implementation that allocates a xfrm_sec_state, populates it using
+ * the supplied security context, and assigns it to the xfrm_state.
+ */
+int selinux_xfrm_state_alloc(struct xfrm_state *x,
+ struct xfrm_user_sec_ctx *uctx)
+{
+ return selinux_xfrm_alloc_user(&x->security, uctx);
}
/*
- * LSM hook implementation that allocs and transfers sec_ctx spec to
- * xfrm_state.
+ * LSM hook implementation that allocates a xfrm_sec_state and populates based
+ * on a secid.
*/
-int selinux_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *uctx,
- u32 secid)
+int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x,
+ struct xfrm_sec_ctx *polsec, u32 secid)
{
- int err;
+ int rc;
+ struct xfrm_sec_ctx *ctx;
+ char *ctx_str = NULL;
+ int str_len;
+
+ if (!polsec)
+ return 0;
- BUG_ON(!x);
+ if (secid == 0)
+ return -EINVAL;
- err = selinux_xfrm_sec_ctx_alloc(&x->security, uctx, secid);
- if (err == 0)
- atomic_inc(&selinux_xfrm_refcount);
- return err;
+ rc = security_sid_to_context(secid, &ctx_str, &str_len);
+ if (rc)
+ return rc;
+
+ ctx = kmalloc(sizeof(*ctx) + str_len, GFP_ATOMIC);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->ctx_doi = XFRM_SC_DOI_LSM;
+ ctx->ctx_alg = XFRM_SC_ALG_SELINUX;
+ ctx->ctx_sid = secid;
+ ctx->ctx_len = str_len;
+ memcpy(ctx->ctx_str, ctx_str, str_len);
+ kfree(ctx_str);
+
+ x->security = ctx;
+ atomic_inc(&selinux_xfrm_refcount);
+ return 0;
}
/*
*/
void selinux_xfrm_state_free(struct xfrm_state *x)
{
- atomic_dec(&selinux_xfrm_refcount);
- kfree(x->security);
+ selinux_xfrm_free(x->security);
}
- /*
- * LSM hook implementation that authorizes deletion of labeled SAs.
- */
+/*
+ * LSM hook implementation that authorizes deletion of labeled SAs.
+ */
int selinux_xfrm_state_delete(struct xfrm_state *x)
{
- const struct task_security_struct *tsec = current_security();
- struct xfrm_sec_ctx *ctx = x->security;
-
- if (!ctx)
- return 0;
-
- return avc_has_perm(tsec->sid, ctx->ctx_sid,
- SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
- NULL);
+ return selinux_xfrm_delete(x->security);
}
/*
* we need to check for unlabelled access since this may not have
* gone thru the IPSec process.
*/
-int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
- struct common_audit_data *ad)
+int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb,
+ struct common_audit_data *ad)
{
- int i, rc = 0;
- struct sec_path *sp;
- u32 sel_sid = SECINITSID_UNLABELED;
-
- sp = skb->sp;
+ int i;
+ struct sec_path *sp = skb->sp;
+ u32 peer_sid = SECINITSID_UNLABELED;
if (sp) {
for (i = 0; i < sp->len; i++) {
if (x && selinux_authorizable_xfrm(x)) {
struct xfrm_sec_ctx *ctx = x->security;
- sel_sid = ctx->ctx_sid;
+ peer_sid = ctx->ctx_sid;
break;
}
}
}
- /*
- * This check even when there's no association involved is
- * intended, according to Trent Jaeger, to make sure a
- * process can't engage in non-ipsec communication unless
- * explicitly allowed by policy.
- */
-
- rc = avc_has_perm(isec_sid, sel_sid, SECCLASS_ASSOCIATION,
- ASSOCIATION__RECVFROM, ad);
-
- return rc;
+ /* This check even when there's no association involved is intended,
+ * according to Trent Jaeger, to make sure a process can't engage in
+ * non-IPsec communication unless explicitly allowed by policy. */
+ return avc_has_perm(sk_sid, peer_sid,
+ SECCLASS_ASSOCIATION, ASSOCIATION__RECVFROM, ad);
}
/*
* If we do have a authorizable security association, then it has already been
* checked in the selinux_xfrm_state_pol_flow_match hook above.
*/
-int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
- struct common_audit_data *ad, u8 proto)
+int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb,
+ struct common_audit_data *ad, u8 proto)
{
struct dst_entry *dst;
- int rc = 0;
-
- dst = skb_dst(skb);
-
- if (dst) {
- struct dst_entry *dst_test;
-
- for (dst_test = dst; dst_test != NULL;
- dst_test = dst_test->child) {
- struct xfrm_state *x = dst_test->xfrm;
-
- if (x && selinux_authorizable_xfrm(x))
- goto out;
- }
- }
switch (proto) {
case IPPROTO_AH:
case IPPROTO_ESP:
case IPPROTO_COMP:
- /*
- * We should have already seen this packet once before
- * it underwent xfrm(s). No need to subject it to the
- * unlabeled check.
- */
- goto out;
+ /* We should have already seen this packet once before it
+ * underwent xfrm(s). No need to subject it to the unlabeled
+ * check. */
+ return 0;
default:
break;
}
- /*
- * This check even when there's no association involved is
- * intended, according to Trent Jaeger, to make sure a
- * process can't engage in non-ipsec communication unless
- * explicitly allowed by policy.
- */
+ dst = skb_dst(skb);
+ if (dst) {
+ struct dst_entry *iter;
- rc = avc_has_perm(isec_sid, SECINITSID_UNLABELED, SECCLASS_ASSOCIATION,
- ASSOCIATION__SENDTO, ad);
-out:
- return rc;
+ for (iter = dst; iter != NULL; iter = iter->child) {
+ struct xfrm_state *x = iter->xfrm;
+
+ if (x && selinux_authorizable_xfrm(x))
+ return 0;
+ }
+ }
+
+ /* This check even when there's no association involved is intended,
+ * according to Trent Jaeger, to make sure a process can't engage in
+ * non-IPsec communication unless explicitly allowed by policy. */
+ return avc_has_perm(sk_sid, SECINITSID_UNLABELED,
+ SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO, ad);
}
projects / linux-drm-fsl-dcu.git / blobdiff