Commit dc5306a8 authored May 08, 2022 by Kees Cook Committed by Paolo Abeni May 10, 2022

decnet: Use container_of() for struct dn_neigh casts



Clang's structure layout randomization feature gets upset when it sees
struct neighbor (which is randomized) cast to struct dn_neigh:

net/decnet/dn_route.c:1123:15: error: casting from randomized structure pointer type 'struct neighbour *' to 'struct dn_neigh *'
			gateway = ((struct dn_neigh *)neigh)->addr;
				   ^

Update all the open-coded casts to use container_of() to do the conversion
instead of depending on strict member ordering.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202205041247.WKBEHGS5-lkp@intel.com


Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Yajun Deng <yajun.deng@linux.dev>
Cc: Zheng Yongjun <zhengyongjun3@huawei.com>
Cc: Bill Wendling <morbo@google.com>
Cc: linux-decnet-user@lists.sourceforge.net
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220508102217.2647184-1-keescook@chromium.org


Signed-off-by: Paolo Abeni <pabeni@redhat.com>

parent 1809c30b

net/decnet/dn_dev.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -854,7 +854,7 @@ static void dn_send_endnode_hello(struct net_device dev, struct dn_ifaddr ifa)
		memcpy(msg->neighbor, dn_hiord, ETH_ALEN);

		if (dn_db->router) {
		struct dn_neigh dn = (struct dn_neigh )dn_db->router;
		struct dn_neigh *dn = container_of(dn_db->router, struct dn_neigh, n);
		dn_dn2eth(msg->neighbor, dn->addr);
		}

		@@ -902,7 +902,7 @@ static void dn_send_router_hello(struct net_device dev, struct dn_ifaddr ifa)
		{
		int n;
		struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);
		struct dn_neigh dn = (struct dn_neigh )dn_db->router;
		struct dn_neigh *dn = container_of(dn_db->router, struct dn_neigh, n);
		struct sk_buff *skb;
		size_t size;
		unsigned char *ptr;

net/decnet/dn_neigh.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -426,7 +426,8 @@ int dn_neigh_router_hello(struct net net, struct sock sk, struct sk_buff *skb)
		if (!dn_db->router) {
		dn_db->router = neigh_clone(neigh);
		} else {
		if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
		if (msg->priority > container_of(dn_db->router,
		struct dn_neigh, n)->priority)
		neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
		}
		}

net/decnet/dn_route.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1120,7 +1120,7 @@ static int dn_route_output_slow(struct dst_entry *pprt, const struct flowidn o
		/* Ok then, we assume its directly connected and move on */
		select_source:
		if (neigh)
		gateway = ((struct dn_neigh *)neigh)->addr;
		gateway = container_of(neigh, struct dn_neigh, n)->addr;
		if (gateway == 0)
		gateway = fld.daddr;
		if (fld.saddr == 0) {
		@@ -1429,7 +1429,7 @@ static int dn_route_input_slow(struct sk_buff *skb)
		/* Use the default router if there is one */
		neigh = neigh_clone(dn_db->router);
		if (neigh) {
		gateway = ((struct dn_neigh *)neigh)->addr;
		gateway = container_of(neigh, struct dn_neigh, n)->addr;
		goto make_route;
		}