From: Jeff Layton jlayton@kernel.org
[ Upstream commit 5085e41f9e83a1bec51da1f20b54f2ec3a13a3fe ]
While the unix_gid object is rcu-freed, the group_info list that it contains is not. Ensure that we only put the group list reference once we are really freeing the unix_gid object.
Reported-by: Zhi Li yieli@redhat.com Link: https://bugzilla.redhat.com/show_bug.cgi?id=2183056 Signed-off-by: Jeff Layton jlayton@kernel.org Fixes: fd5d2f78261b ("SUNRPC: Make server side AUTH_UNIX use lockless lookups") Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/sunrpc/svcauth_unix.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c index b1efc34db6ed8..609ade4fb49ed 100644 --- a/net/sunrpc/svcauth_unix.c +++ b/net/sunrpc/svcauth_unix.c @@ -416,14 +416,23 @@ static int unix_gid_hash(kuid_t uid) return hash_long(from_kuid(&init_user_ns, uid), GID_HASHBITS); }
-static void unix_gid_put(struct kref *kref) +static void unix_gid_free(struct rcu_head *rcu) { - struct cache_head *item = container_of(kref, struct cache_head, ref); - struct unix_gid *ug = container_of(item, struct unix_gid, h); + struct unix_gid *ug = container_of(rcu, struct unix_gid, rcu); + struct cache_head *item = &ug->h; + if (test_bit(CACHE_VALID, &item->flags) && !test_bit(CACHE_NEGATIVE, &item->flags)) put_group_info(ug->gi); - kfree_rcu(ug, rcu); + kfree(ug); +} + +static void unix_gid_put(struct kref *kref) +{ + struct cache_head *item = container_of(kref, struct cache_head, ref); + struct unix_gid *ug = container_of(item, struct unix_gid, h); + + call_rcu(&ug->rcu, unix_gid_free); }
static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)