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authorBenedict Wong <benedictwong@google.com>2023-05-10 01:30:21 +0000
committerSteffen Klassert <steffen.klassert@secunet.com>2023-05-21 09:21:37 +0200
commit1f8b6df6a997a430b0c48b504638154b520781ad (patch)
treee74b3e927438f0e59ad49d7e8bb40c18b92f0af9 /net/xfrm/xfrm_policy.c
parent67caf26d769e0cb17dba182b0acae015c7aa5881 (diff)
xfrm: Treat already-verified secpath entries as optional
This change allows inbound traffic through nested IPsec tunnels to successfully match policies and templates, while retaining the secpath stack trace as necessary for netfilter policies. Specifically, this patch marks secpath entries that have already matched against a relevant policy as having been verified, allowing it to be treated as optional and skipped after a tunnel decapsulation (during which the src/dst/proto/etc may have changed, and the correct policy chain no long be resolvable). This approach is taken as opposed to the iteration in b0355dbbf13c, where the secpath was cleared, since that breaks subsequent validations that rely on the existence of the secpath entries (netfilter policies, or transport-in-tunnel mode, where policies remain resolvable). Fixes: b0355dbbf13c ("Fix XFRM-I support for nested ESP tunnels") Test: Tested against Android Kernel Unit Tests Test: Tested against Android CTS Signed-off-by: Benedict Wong <benedictwong@google.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm/xfrm_policy.c')
-rw-r--r--net/xfrm/xfrm_policy.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 6d15788b5123..ff58ce6c030c 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -3349,6 +3349,13 @@ xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int star
if (xfrm_state_ok(tmpl, sp->xvec[idx], family, if_id))
return ++idx;
if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
+ if (idx < sp->verified_cnt) {
+ /* Secpath entry previously verified, consider optional and
+ * continue searching
+ */
+ continue;
+ }
+
if (start == -1)
start = -2-idx;
break;
@@ -3723,6 +3730,9 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
* Order is _important_. Later we will implement
* some barriers, but at the moment barriers
* are implied between each two transformations.
+ * Upon success, marks secpath entries as having been
+ * verified to allow them to be skipped in future policy
+ * checks (e.g. nested tunnels).
*/
for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
k = xfrm_policy_ok(tpp[i], sp, k, family, if_id);
@@ -3741,6 +3751,8 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
}
xfrm_pols_put(pols, npols);
+ sp->verified_cnt = k;
+
return 1;
}
XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);