Merge branch 'net-introduce-struct-sockaddr_unsized'

Kees Cook says:

====================
net: Introduce struct sockaddr_unsized

The historically fixed-size struct sockaddr is part of UAPI and embedded
in many existing structures. The kernel uses struct sockaddr extensively
within the kernel to represent arbitrarily sized sockaddr structures,
which caused problems with the compiler's ability to determine object
sizes correctly. The "temporary" solution was to make sockaddr explicitly
use a flexible array, but this causes problems for embedding struct
sockaddr in structures, where once again the compiler has to guess about
the size of such objects, and causes thousands of warnings under the
coming -Wflex-array-member-not-at-end warning.

Switching to sockaddr_storage internally everywhere wastes a lot of memory,
so we are left with needing two changes:
- introduction of an explicitly arbitrarily sized sockaddr struct
- switch struct sockaddr back to being fixed size

Doing the latter step requires all "arbitrarily sized" uses of struct
sockaddr to be replaced with the new struct from the first step.

So, introduce the new struct and do enough conversions that we can
switch sockaddr back to a fixed-size sa_data.
====================

Link: https://patch.msgid.link/20251104002608.do.383-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/net/socket.c b/net/socket.c
index e8892b218708..101a7ed574e7 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1872,7 +1872,7 @@ int __sys_bind_socket(struct socket *sock, struct sockaddr_storage *address,
 				   addrlen);
 	if (!err)
 		err = READ_ONCE(sock->ops)->bind(sock,
-						 (struct sockaddr *)address,
+						 (struct sockaddr_unsized *)address,
 						 addrlen);
 	return err;
 }
@@ -2099,8 +2099,8 @@ int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
 	if (err)
 		goto out;
 
-	err = READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)address,
-				addrlen, sock->file->f_flags | file_flags);
+	err = READ_ONCE(sock->ops)->connect(sock, (struct sockaddr_unsized *)address,
+					    addrlen, sock->file->f_flags | file_flags);
 out:
 	return err;
 }
@@ -3583,13 +3583,13 @@ static long compat_sock_ioctl(struct file *file, unsigned int cmd,
  *	Returns 0 or an error.
  */
 
-int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
+int kernel_bind(struct socket *sock, struct sockaddr_unsized *addr, int addrlen)
 {
 	struct sockaddr_storage address;
 
 	memcpy(&address, addr, addrlen);
 
-	return READ_ONCE(sock->ops)->bind(sock, (struct sockaddr *)&address,
+	return READ_ONCE(sock->ops)->bind(sock, (struct sockaddr_unsized *)&address,
 					  addrlen);
 }
 EXPORT_SYMBOL(kernel_bind);
@@ -3662,14 +3662,14 @@ EXPORT_SYMBOL(kernel_accept);
  *	Returns 0 or an error code.
  */
 
-int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
+int kernel_connect(struct socket *sock, struct sockaddr_unsized *addr, int addrlen,
 		   int flags)
 {
 	struct sockaddr_storage address;
 
 	memcpy(&address, addr, addrlen);
 
-	return READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)&address,
+	return READ_ONCE(sock->ops)->connect(sock, (struct sockaddr_unsized *)&address,
 					     addrlen, flags);
 }
 EXPORT_SYMBOL(kernel_connect);