diff mbox series

decnet: Use container_of() for struct dn_neigh casts

Message ID 20220508102217.2647184-1-keescook@chromium.org (mailing list archive)
State Accepted
Commit dc5306a8c0eace6c113aded2e36ae5e15fdca4d7
Delegated to: Netdev Maintainers
Headers show
Series decnet: Use container_of() for struct dn_neigh casts | expand

Checks

Context Check Description
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 2 maintainers not CCed: edumazet@google.com llvm@lists.linux.dev
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch warning WARNING: line length of 86 exceeds 80 columns WARNING: line length of 95 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Kees Cook May 8, 2022, 10:22 a.m. UTC 
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>
---
 net/decnet/dn_dev.c   | 4 ++--
 net/decnet/dn_neigh.c | 3 ++-
 net/decnet/dn_route.c | 4 ++--
 3 files changed, 6 insertions(+), 5 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org May 10, 2022, 10:40 a.m. UTC | #1 
Hello:

This patch was applied to netdev/net.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Sun,  8 May 2022 03:22:17 -0700 you wrote:
> 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;
> 				   ^
> 
> [...]

Here is the summary with links:
  - decnet: Use container_of() for struct dn_neigh casts
    https://git.kernel.org/netdev/net/c/dc5306a8c0ea

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 0ee7d4c0c955..a09ba642b5e7 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -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;
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index 94b306f6d551..fbd98ac853ea 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -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)));
 			}
 		}
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 7e85f2a1ae25..d1d78a463a06 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -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;
 		}