The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

bedc8f76b353 ("cifs: always initialize struct msghdr smb_msg completely") 17d3df38dc5f ("cifs: don't send down the destination address to sendmsg for a SOCK_STREAM") cf0604a686b1 ("cifs: use discard iterator to discard unneeded network data more efficiently") db10538a4b99 ("tcp: add tcp_sock_set_cork")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bedc8f76b3539ac4f952114b316bcc2251e808ce Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher metze@samba.org Date: Wed, 14 Sep 2022 05:25:47 +0200 Subject: [PATCH] cifs: always initialize struct msghdr smb_msg completely

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@samba.org Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (SUSE) pc@cjr.nz Reviewed-by: Ronnie Sahlberg lsahlber@redhat.com Signed-off-by: Steve French stfrench@microsoft.com

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index a0a06b6f252b..0225f4c8adf0 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -702,9 +702,6 @@ 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();

@@ -760,7 +757,7 @@ 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);

@@ -770,15 +767,13 @@ cifs_read_from_socket(struct TCP_Server_Info *server, char *buf, ssize_t cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read) { - struct msghdr smb_msg; + struct msghdr smb_msg = {};

/* * iov_iter_discard already sets smb_msg.type and count and iov_offset * and cifs_readv_from_socket sets msg_control and msg_controllen * so little to initialize in struct msghdr */ - smb_msg.msg_name = NULL; - smb_msg.msg_namelen = 0; iov_iter_discard(&smb_msg.msg_iter, READ, to_read);

return cifs_readv_from_socket(server, &smb_msg); @@ -788,7 +783,7 @@ 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 a43c87c1d343..9a2753e21170 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -194,10 +194,6 @@ 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 @@ -309,7 +305,7 @@ __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 = {}; __be32 rfc1002_marker;

if (cifs_rdma_enabled(server)) {