LSM: Make the Labeled IPsec hooks more stack friendly
The xfrm_get_policy() and xfrm_add_pol_expire() put some rather large structs
on the stack to work around the LSM API. This patch attempts to fix that
problem by changing the LSM API to require only the relevant "security"
pointers instead of the entire SPD entry; we do this for all of the
security_xfrm_policy*() functions to keep things consistent.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 5578c90..ecf9d67 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -959,7 +959,7 @@
return 0;
uctx = nla_data(rt);
- return security_xfrm_policy_alloc(pol, uctx);
+ return security_xfrm_policy_alloc(&pol->security, uctx);
}
static void copy_templates(struct xfrm_policy *xp, struct xfrm_user_tmpl *ut,
@@ -1143,7 +1143,7 @@
NETLINK_CB(skb).sid);
if (err) {
- security_xfrm_policy_free(xp);
+ security_xfrm_policy_free(xp->security);
kfree(xp);
return err;
}
@@ -1337,22 +1337,23 @@
xp = xfrm_policy_byid(type, p->dir, p->index, delete, &err);
else {
struct nlattr *rt = attrs[XFRMA_SEC_CTX];
- struct xfrm_policy tmp;
+ struct xfrm_sec_ctx *ctx;
err = verify_sec_ctx_len(attrs);
if (err)
return err;
- memset(&tmp, 0, sizeof(struct xfrm_policy));
if (rt) {
struct xfrm_user_sec_ctx *uctx = nla_data(rt);
- if ((err = security_xfrm_policy_alloc(&tmp, uctx)))
+ err = security_xfrm_policy_alloc(&ctx, uctx);
+ if (err)
return err;
- }
- xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, tmp.security,
+ } else
+ ctx = NULL;
+ xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, ctx,
delete, &err);
- security_xfrm_policy_free(&tmp);
+ security_xfrm_policy_free(ctx);
}
if (xp == NULL)
return -ENOENT;
@@ -1572,26 +1573,26 @@
xp = xfrm_policy_byid(type, p->dir, p->index, 0, &err);
else {
struct nlattr *rt = attrs[XFRMA_SEC_CTX];
- struct xfrm_policy tmp;
+ struct xfrm_sec_ctx *ctx;
err = verify_sec_ctx_len(attrs);
if (err)
return err;
- memset(&tmp, 0, sizeof(struct xfrm_policy));
if (rt) {
struct xfrm_user_sec_ctx *uctx = nla_data(rt);
- if ((err = security_xfrm_policy_alloc(&tmp, uctx)))
+ err = security_xfrm_policy_alloc(&ctx, uctx);
+ if (err)
return err;
- }
- xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, tmp.security,
- 0, &err);
- security_xfrm_policy_free(&tmp);
+ } else
+ ctx = NULL;
+ xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, ctx, 0, &err);
+ security_xfrm_policy_free(ctx);
}
-
if (xp == NULL)
return -ENOENT;
+
read_lock(&xp->lock);
if (xp->dead) {
read_unlock(&xp->lock);