Patch "cifs: always initialize struct msghdr smb_msg completely" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cifs: always initialize struct msghdr smb_msg completely

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cifs-always-initialize-struct-msghdr-smb_msg-complet.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 547a033ddf6213ee46912eace139efca383ca28a
Author: Stefan Metzmacher <metze@xxxxxxxxx>
Date:   Wed Sep 14 05:25:47 2022 +0200

    cifs: always initialize struct msghdr smb_msg completely
    
    [ Upstream commit bedc8f76b3539ac4f952114b316bcc2251e808ce ]
    
    So far we were just lucky because the uninitialized members
    of struct msghdr are not used by default on a SOCK_STREAM tcp
    socket.
    
    But as new things like msg_ubuf and sg_from_iter where added
    recently, we should play on the safe side and avoid potention
    problems in future.
    
    Signed-off-by: Stefan Metzmacher <metze@xxxxxxxxx>
    Cc: stable@xxxxxxxxxxxxxxx
    Reviewed-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
    Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
    Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 86bdebd2ece6..f8127edb8973 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -791,9 +791,6 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 	int length = 0;
 	int total_read;
 
-	smb_msg->msg_control = NULL;
-	smb_msg->msg_controllen = 0;
-
 	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 		try_to_freeze();
 
@@ -844,7 +841,7 @@ int
 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 		      unsigned int to_read)
 {
-	struct msghdr smb_msg;
+	struct msghdr smb_msg = {};
 	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 	iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 
@@ -855,7 +852,7 @@ int
 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 	unsigned int page_offset, unsigned int to_read)
 {
-	struct msghdr smb_msg;
+	struct msghdr smb_msg = {};
 	struct bio_vec bv = {
 		.bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 	iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 079a4f6162ed..b98ae69edb8f 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -209,10 +209,6 @@ smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
 
 	*sent = 0;
 
-	smb_msg->msg_name = NULL;
-	smb_msg->msg_namelen = 0;
-	smb_msg->msg_control = NULL;
-	smb_msg->msg_controllen = 0;
 	if (server->noblocksnd)
 		smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
 	else
@@ -324,7 +320,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 	sigset_t mask, oldmask;
 	size_t total_len = 0, sent, size;
 	struct socket *ssocket = server->ssocket;
-	struct msghdr smb_msg;
+	struct msghdr smb_msg = {};
 	int val = 1;
 	__be32 rfc1002_marker;