From c1aca3080e382886e2e58e809787441984a2f89b Mon Sep 17 00:00:00 2001 From: Yan Yan Date: Tue, 18 Jan 2022 16:00:13 -0800 Subject: xfrm: Check if_id in xfrm_migrate This patch enables distinguishing SAs and SPs based on if_id during the xfrm_migrate flow. This ensures support for xfrm interfaces throughout the SA/SP lifecycle. When there are multiple existing SPs with the same direction, the same xfrm_selector and different endpoint addresses, xfrm_migrate might fail with ENODATA. Specifically, the code path for performing xfrm_migrate is: Stage 1: find policy to migrate with xfrm_migrate_policy_find(sel, dir, type, net) Stage 2: find and update state(s) with xfrm_migrate_state_find(mp, net) Stage 3: update endpoint address(es) of template(s) with xfrm_policy_migrate(pol, m, num_migrate) Currently "Stage 1" always returns the first xfrm_policy that matches, and "Stage 3" looks for the xfrm_tmpl that matches the old endpoint address. Thus if there are multiple xfrm_policy with same selector, direction, type and net, "Stage 1" might rertun a wrong xfrm_policy and "Stage 3" will fail with ENODATA because it cannot find a xfrm_tmpl with the matching endpoint address. The fix is to allow userspace to pass an if_id and add if_id to the matching rule in Stage 1 and Stage 2 since if_id is a unique ID for xfrm_policy and xfrm_state. For compatibility, if_id will only be checked if the attribute is set. Tested with additions to Android's kernel unit test suite: https://android-review.googlesource.com/c/kernel/tests/+/1668886 Signed-off-by: Yan Yan Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_user.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net/xfrm/xfrm_user.c') diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 8cd6c8129004..a4fb596e87af 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -2608,6 +2608,7 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh, int n = 0; struct net *net = sock_net(skb->sk); struct xfrm_encap_tmpl *encap = NULL; + u32 if_id = 0; if (attrs[XFRMA_MIGRATE] == NULL) return -EINVAL; @@ -2632,7 +2633,10 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh, return -ENOMEM; } - err = xfrm_migrate(&pi->sel, pi->dir, type, m, n, kmp, net, encap); + if (attrs[XFRMA_IF_ID]) + if_id = nla_get_u32(attrs[XFRMA_IF_ID]); + + err = xfrm_migrate(&pi->sel, pi->dir, type, m, n, kmp, net, encap, if_id); kfree(encap); -- cgit v1.2.3