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authorHerbert Xu <herbert@gondor.apana.org.au>2017-03-14 13:25:57 +0300
committerDavid S. Miller <davem@davemloft.net>2017-03-22 00:38:15 +0300
commit8a0f5ccfb33b0b8b51de65b7b3bf342ba10b4fb6 (patch)
tree7ee2aabab355f030568c83095f1c13d455e1b564 /net/netlink
parent98d068ab52b4b11d403995ed14154660797e7136 (diff)
downloadlinux-8a0f5ccfb33b0b8b51de65b7b3bf342ba10b4fb6.tar.xz
crypto: deadlock between crypto_alg_sem/rtnl_mutex/genl_mutex
On Tue, Mar 14, 2017 at 10:44:10AM +0100, Dmitry Vyukov wrote: > > Yes, please. > Disregarding some reports is not a good way long term. Please try this patch. ---8<--- Subject: netlink: Annotate nlk cb_mutex by protocol Currently all occurences of nlk->cb_mutex are annotated by lockdep as a single class. This causes a false lcokdep cycle involving genl and crypto_user. This patch fixes it by dividing cb_mutex into individual classes based on the netlink protocol. As genl and crypto_user do not use the same netlink protocol this breaks the false dependency loop. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
-rw-r--r--net/netlink/af_netlink.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7b73c7c161a9..596eaff66649 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -96,6 +96,44 @@ EXPORT_SYMBOL_GPL(nl_table);
static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
+static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS];
+
+static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = {
+ "nlk_cb_mutex-ROUTE",
+ "nlk_cb_mutex-1",
+ "nlk_cb_mutex-USERSOCK",
+ "nlk_cb_mutex-FIREWALL",
+ "nlk_cb_mutex-SOCK_DIAG",
+ "nlk_cb_mutex-NFLOG",
+ "nlk_cb_mutex-XFRM",
+ "nlk_cb_mutex-SELINUX",
+ "nlk_cb_mutex-ISCSI",
+ "nlk_cb_mutex-AUDIT",
+ "nlk_cb_mutex-FIB_LOOKUP",
+ "nlk_cb_mutex-CONNECTOR",
+ "nlk_cb_mutex-NETFILTER",
+ "nlk_cb_mutex-IP6_FW",
+ "nlk_cb_mutex-DNRTMSG",
+ "nlk_cb_mutex-KOBJECT_UEVENT",
+ "nlk_cb_mutex-GENERIC",
+ "nlk_cb_mutex-17",
+ "nlk_cb_mutex-SCSITRANSPORT",
+ "nlk_cb_mutex-ECRYPTFS",
+ "nlk_cb_mutex-RDMA",
+ "nlk_cb_mutex-CRYPTO",
+ "nlk_cb_mutex-SMC",
+ "nlk_cb_mutex-23",
+ "nlk_cb_mutex-24",
+ "nlk_cb_mutex-25",
+ "nlk_cb_mutex-26",
+ "nlk_cb_mutex-27",
+ "nlk_cb_mutex-28",
+ "nlk_cb_mutex-29",
+ "nlk_cb_mutex-30",
+ "nlk_cb_mutex-31",
+ "nlk_cb_mutex-MAX_LINKS"
+};
+
static int netlink_dump(struct sock *sk);
static void netlink_skb_destructor(struct sk_buff *skb);
@@ -585,6 +623,9 @@ static int __netlink_create(struct net *net, struct socket *sock,
} else {
nlk->cb_mutex = &nlk->cb_def_mutex;
mutex_init(nlk->cb_mutex);
+ lockdep_set_class_and_name(nlk->cb_mutex,
+ nlk_cb_mutex_keys + protocol,
+ nlk_cb_mutex_key_strings[protocol]);
}
init_waitqueue_head(&nlk->wait);