This is a note to let you know that I've just added the patch titled
cifs: To match file servers, make sure the server hostname matches
to the 5.14-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-to-match-file-servers-make-sure-the-server-hostname-matches.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7be3248f313930ff3d3436d4e9ddbe9fccc1f541 Mon Sep 17 00:00:00 2001
From: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Date: Thu, 14 Oct 2021 11:52:39 +0000
Subject: cifs: To match file servers, make sure the server hostname matches
From: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
commit 7be3248f313930ff3d3436d4e9ddbe9fccc1f541 upstream.
We generally rely on a bunch of factors to differentiate between servers.
For example, IP address, port etc.
For certain server types (like Azure), it is important to make sure
that the server hostname matches too, even if the both hostnames currently
resolve to the same IP address.
Signed-off-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/connect.c | 19 +++++++++++--------
fs/cifs/fs_context.c | 8 ++++++++
fs/cifs/fs_context.h | 1 +
3 files changed, 20 insertions(+), 8 deletions(-)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -795,7 +795,6 @@ static void clean_demultiplex_info(struc
*/
}
- kfree(server->hostname);
kfree(server);
length = atomic_dec_return(&tcpSesAllocCount);
@@ -1236,6 +1235,9 @@ static int match_server(struct TCP_Serve
if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
return 0;
+ if (strcasecmp(server->hostname, ctx->server_hostname))
+ return 0;
+
if (!match_address(server, addr,
(struct sockaddr *)&ctx->srcaddr))
return 0;
@@ -1337,6 +1339,7 @@ cifs_put_tcp_session(struct TCP_Server_I
kfree(server->session_key.response);
server->session_key.response = NULL;
server->session_key.len = 0;
+ kfree(server->hostname);
task = xchg(&server->tsk, NULL);
if (task)
@@ -1362,14 +1365,15 @@ cifs_get_tcp_session(struct smb3_fs_cont
goto out_err;
}
+ tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
+ if (!tcp_ses->hostname) {
+ rc = -ENOMEM;
+ goto out_err;
+ }
+
tcp_ses->ops = ctx->ops;
tcp_ses->vals = ctx->vals;
cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
- tcp_ses->hostname = extract_hostname(ctx->UNC);
- if (IS_ERR(tcp_ses->hostname)) {
- rc = PTR_ERR(tcp_ses->hostname);
- goto out_err_crypto_release;
- }
tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
tcp_ses->noblockcnt = ctx->rootfs;
@@ -1498,8 +1502,7 @@ out_err_crypto_release:
out_err:
if (tcp_ses) {
- if (!IS_ERR(tcp_ses->hostname))
- kfree(tcp_ses->hostname);
+ kfree(tcp_ses->hostname);
if (tcp_ses->ssocket)
sock_release(tcp_ses->ssocket);
kfree(tcp_ses);
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -332,6 +332,7 @@ smb3_fs_context_dup(struct smb3_fs_conte
DUP_CTX_STR(mount_options);
DUP_CTX_STR(username);
DUP_CTX_STR(password);
+ DUP_CTX_STR(server_hostname);
DUP_CTX_STR(UNC);
DUP_CTX_STR(source);
DUP_CTX_STR(domainname);
@@ -470,6 +471,11 @@ smb3_parse_devname(const char *devname,
if (!pos)
return -EINVAL;
+ /* record the server hostname */
+ ctx->server_hostname = kstrndup(devname + 2, pos - devname - 2, GFP_KERNEL);
+ if (!ctx->server_hostname)
+ return -ENOMEM;
+
/* skip past delimiter */
++pos;
@@ -1510,6 +1516,8 @@ smb3_cleanup_fs_context_contents(struct
ctx->username = NULL;
kfree_sensitive(ctx->password);
ctx->password = NULL;
+ kfree(ctx->server_hostname);
+ ctx->server_hostname = NULL;
kfree(ctx->UNC);
ctx->UNC = NULL;
kfree(ctx->source);
--- a/fs/cifs/fs_context.h
+++ b/fs/cifs/fs_context.h
@@ -169,6 +169,7 @@ struct smb3_fs_context {
char *password;
char *domainname;
char *source;
+ char *server_hostname;
char *UNC;
char *nodename;
char *iocharset; /* local code page for mapping to and from Unicode */
Patches currently in stable-queue which might be from sprasad@xxxxxxxxxxxxx are
queue-5.14/cifs-set-a-minimum-of-120s-for-next-dns-resolution.patch
queue-5.14/cifs-to-match-file-servers-make-sure-the-server-hostname-matches.patch
