xfrm: Fix a race in the xdst pcpu cache. (76a42011) · Commits · 戴 / test

We need to run xfrm_resolve_and_create_bundle() with bottom halves off. Otherwise we may reuse an already released dst_enty when the xfrm lookup functions are called from process context. Fixes: c30d78c14a813db39a647b6a348b428 ("xfrm: add xdst pcpu cache") Reported-by:

Darius Ski <darius.ski@gmail.com> Signed-off-by:

Steffen Klassert <steffen.klassert@secunet.com>

net/xfrm/xfrm_policy.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -2063,8 +2063,11 @@ xfrm_bundle_lookup(struct net net, const struct flowi fl, u16 family, u8 dir,
		if (num_xfrms <= 0)
		goto make_dummy_bundle;

		local_bh_disable();
		xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
		xflo->dst_orig);
		local_bh_enable();

		if (IS_ERR(xdst)) {
		err = PTR_ERR(xdst);
		if (err != -EAGAIN)
		@@ -2151,9 +2154,12 @@ struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
		goto no_transform;
		}

		local_bh_disable();
		xdst = xfrm_resolve_and_create_bundle(
		pols, num_pols, fl,
		family, dst_orig);
		local_bh_enable();

		if (IS_ERR(xdst)) {
		xfrm_pols_put(pols, num_pols);
		err = PTR_ERR(xdst);

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