From ceab06885c09f685910779a8685b7659d66de4b5 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Wed, 10 Jan 2018 12:14:28 +0100 Subject: [PATCH] xfrm: Fix a race in the xdst pcpu cache. commit 76a4201191814a0061cb5c861fafb9ecaa764846 upstream. 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 Signed-off-by: Steffen Klassert Acked-by: David Miller , Signed-off-by: Greg Kroah-Hartman --- net/xfrm/xfrm_policy.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 6bc16bb..688ed34 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -2056,8 +2056,11 @@ 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); + xflo->dst_orig); + local_bh_enable(); + if (IS_ERR(xdst)) { err = PTR_ERR(xdst); if (err != -EAGAIN) @@ -2144,9 +2147,12 @@ 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); -- 2.7.4