From: Pavel Emelyanov Date: Fri, 14 Dec 2007 19:38:04 +0000 (-0800) Subject: [XFRM]: Fix potential race vs xfrm_state(only)_find and xfrm_hash_resize. X-Git-Tag: v2.6.25-rc1~1162^2~1080 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4bda4f250d21c3e4f2a2da5f4cef829a434a4046;p=linux-2.6 [XFRM]: Fix potential race vs xfrm_state(only)_find and xfrm_hash_resize. The _find calls calculate the hash value using the xfrm_state_hmask, without the xfrm_state_lock. But the value of this mask can change in the _resize call under the state_lock, so we risk to fail in finding the desired entry in hash. I think, that the hash value is better to calculate under the state lock. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index b2343d48fe..f7c0951c9f 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -756,7 +756,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr, struct xfrm_policy *pol, int *err, unsigned short family) { - unsigned int h = xfrm_dst_hash(daddr, saddr, tmpl->reqid, family); + unsigned int h; struct hlist_node *entry; struct xfrm_state *x, *x0; int acquire_in_progress = 0; @@ -764,6 +764,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr, struct xfrm_state *best = NULL; spin_lock_bh(&xfrm_state_lock); + h = xfrm_dst_hash(daddr, saddr, tmpl->reqid, family); hlist_for_each_entry(x, entry, xfrm_state_bydst+h, bydst) { if (x->props.family == family && x->props.reqid == tmpl->reqid && @@ -865,11 +866,12 @@ struct xfrm_state * xfrm_stateonly_find(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, u8 mode, u8 proto, u32 reqid) { - unsigned int h = xfrm_dst_hash(daddr, saddr, reqid, family); + unsigned int h; struct xfrm_state *rx = NULL, *x = NULL; struct hlist_node *entry; spin_lock(&xfrm_state_lock); + h = xfrm_dst_hash(daddr, saddr, reqid, family); hlist_for_each_entry(x, entry, xfrm_state_bydst+h, bydst) { if (x->props.family == family && x->props.reqid == reqid &&