[PATCH 5.16 034/126] cifs: fix workstation_name for multiuser mounts

[Greg Kroah-Hartman]

From: Ryan Bair <ryandbair@xxxxxxxxx>

commit d3b331fb51f326d5b5326010bf2b5841bb86cdc6 upstream.

Set workstation_name from the master_tcon for multiuser mounts.

Just in case, protect size_of_ntlmssp_blob against a NULL workstation_name.

Fixes: 49bd49f983b5 ("cifs: send workstation name during ntlmssp session setup")
Cc: stable@xxxxxxxxxxxxxxx # 5.16
Reviewed-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
Signed-off-by: Ryan Bair <ryandbair@xxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/cifs/connect.c |   13 +++++++++++++
 fs/cifs/sess.c    |    6 +++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1945,6 +1945,19 @@ cifs_set_cifscreds(struct smb3_fs_contex
 		}
 	}
 
+	ctx->workstation_name = kstrdup(ses->workstation_name, GFP_KERNEL);
+	if (!ctx->workstation_name) {
+		cifs_dbg(FYI, "Unable to allocate memory for workstation_name\n");
+		rc = -ENOMEM;
+		kfree(ctx->username);
+		ctx->username = NULL;
+		kfree_sensitive(ctx->password);
+		ctx->password = NULL;
+		kfree(ctx->domainname);
+		ctx->domainname = NULL;
+		goto out_key_put;
+	}
+
 out_key_put:
 	up_read(&key->sem);
 	key_put(key);
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -675,7 +675,11 @@ static int size_of_ntlmssp_blob(struct c
 	else
 		sz += sizeof(__le16);
 
-	sz += sizeof(__le16) * strnlen(ses->workstation_name, CIFS_MAX_WORKSTATION_LEN);
+	if (ses->workstation_name)
+		sz += sizeof(__le16) * strnlen(ses->workstation_name,
+			CIFS_MAX_WORKSTATION_LEN);
+	else
+		sz += sizeof(__le16);
 
 	return sz;
 }