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authorPaul Moore <pmoore@redhat.com>2013-07-24 01:38:38 +0400
committerEric Paris <eparis@redhat.com>2013-07-25 21:01:25 +0400
commit2e5aa86609ec1cf37bcc204fd7ba6c24c2f49fec (patch)
treedfe240f974ba5437143fa8869813ac634731d860 /security/selinux/xfrm.c
parent8bb495e3f02401ee6f76d1b1d77f3ac9f079e376 (diff)
downloadlinux-2e5aa86609ec1cf37bcc204fd7ba6c24c2f49fec.tar.xz
lsm: split the xfrm_state_alloc_security() hook implementation
The xfrm_state_alloc_security() LSM hook implementation is really a multiplexed hook with two different behaviors depending on the arguments passed to it by the caller. This patch splits the LSM hook implementation into two new hook implementations, which match the LSM hooks in the rest of the kernel: * xfrm_state_alloc * xfrm_state_alloc_acquire Also included in this patch are the necessary changes to the SELinux code; no other LSMs are affected. Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'security/selinux/xfrm.c')
-rw-r--r--security/selinux/xfrm.c199
1 files changed, 90 insertions, 109 deletions
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index d03081886214..07ae0c06dfc3 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -74,6 +74,54 @@ static inline int selinux_authorizable_xfrm(struct xfrm_state *x)
}
/*
+ * Allocates a xfrm_sec_state and populates it using the supplied security
+ * xfrm_user_sec_ctx context.
+ */
+static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp,
+ struct xfrm_user_sec_ctx *uctx)
+{
+ int rc;
+ const struct task_security_struct *tsec = current_security();
+ struct xfrm_sec_ctx *ctx = NULL;
+ u32 str_len;
+
+ if (ctxp == NULL || uctx == NULL ||
+ uctx->ctx_doi != XFRM_SC_DOI_LSM ||
+ uctx->ctx_alg != XFRM_SC_ALG_SELINUX)
+ return -EINVAL;
+
+ str_len = uctx->ctx_len;
+ if (str_len >= PAGE_SIZE)
+ return -ENOMEM;
+
+ 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;
+}
+
+/*
* LSM hook implementation that authorizes that a flow can use
* a xfrm policy rule.
*/
@@ -191,111 +239,13 @@ int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
}
/*
- * 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;
-}
-
-/*
* 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);
}
@@ -347,20 +297,51 @@ int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx)
}
/*
- * LSM hook implementation that allocs and transfers sec_ctx spec to
- * xfrm_state.
+ * 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 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;
- BUG_ON(!x);
+ if (!polsec)
+ return 0;
- err = selinux_xfrm_sec_ctx_alloc(&x->security, uctx, secid);
- if (err == 0)
- atomic_inc(&selinux_xfrm_refcount);
- return err;
+ if (secid == 0)
+ return -EINVAL;
+
+ 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;
}
/*