From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Fri, 13 Mar 2015 01:54:10 +0000 (+1100)
Subject: rhashtable: Fix read-side crash during rehash
X-Git-Tag: v4.1-rc1~128^2~251
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=393619474ec0ba2a16dee12ec78fd43164f1e9b7;p=linux.git

rhashtable: Fix read-side crash during rehash

This patch fixes a typo rhashtable_lookup_compare where we fail
to recompute the hash when looking up the new table.  This causes
elements to be missed and potentially a crash during a resize.

Reported-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index adea791ea3ab..fc0d451279f0 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -606,8 +606,8 @@ void *rhashtable_lookup_compare(struct rhashtable *ht, const void *key,
 	rcu_read_lock();
 
 	tbl = rht_dereference_rcu(ht->tbl, ht);
-	hash = key_hashfn(ht, tbl, key);
 restart:
+	hash = key_hashfn(ht, tbl, key);
 	rht_for_each_rcu(he, tbl, hash) {
 		if (!compare(rht_obj(ht, he), arg))
 			continue;