From fcd7e9af33132c0ca397bba35b8ca58d54548127 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Fri, 26 Jun 2015 13:48:17 +0300 Subject: lib/rhashtable: fix race between rhashtable_lookup_compare and hashtable resize Hash value passed as argument into rhashtable_lookup_compare could be computed using different hash table than rhashtable_lookup_compare sees. This patch passes key into rhashtable_lookup_compare() instead of hash and compures hash value right in place using the same table as for lookup. Also it adds comment for rhashtable_hashfn and rhashtable_obj_hashfn: user must prevent concurrent insert/remove otherwise returned hash value could be invalid. Signed-off-by: Konstantin Khlebnikov Fixes: e341694e3eb5 ("netlink: Convert netlink_lookup() to use RCU protected hash table") Link: http://lkml.kernel.org/r/20150514042151.GA5482@gondor.apana.org.au Cc: Stable (v3.17 .. v3.19) Signed-off-by: Sasha Levin --- include/linux/rhashtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index fb298e9d6d3a..84056743780a 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -108,7 +108,7 @@ int rhashtable_expand(struct rhashtable *ht, gfp_t flags); int rhashtable_shrink(struct rhashtable *ht, gfp_t flags); void *rhashtable_lookup(const struct rhashtable *ht, const void *key); -void *rhashtable_lookup_compare(const struct rhashtable *ht, u32 hash, +void *rhashtable_lookup_compare(const struct rhashtable *ht, void *key, bool (*compare)(void *, void *), void *arg); void rhashtable_destroy(const struct rhashtable *ht); -- cgit v1.2.3