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

Greg Kroah-Hartman
2022-02-07T12:03:25Z

From: Ryan Bair <ryandbair@gmail.com>

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@vger.kernel.org # 5.16
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Ryan Bair <ryandbair@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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;
}