[CIFS] Make sec=none force an anonymous mount

We had a customer report that attempting to make CIFS mount with a null
username (i.e. doing an anonymous mount) doesn't work. Looking through the
code, it looks like CIFS expects a NULL username from userspace in order
to trigger an anonymous mount. The mount.cifs code doesn't seem to ever
pass a null username to the kernel, however.

It looks also like the kernel can take a sec=none option, but it only seems
to look at it if the username is already NULL. This seems redundant and
effectively makes sec=none useless.

The following patch makes sec=none force an anonymous mount.

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index 62dcf6325861..a9b6bc5157b8 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -6,7 +6,9 @@ handle DNS host to ipv6 name translation).  Accept override of uid or gid
 on mount even when Unix Extensions are negotiated (it used to be ignored
 when Unix Extensions were ignored).  This allows users to override the
 default uid and gid for files when they are certain that the uids or
-gids on the server do not match those of the client.
+gids on the server do not match those of the client.  Make "sec=none"
+mount override username (so that null user connection is attempted)
+to match what documentation said.
 
 Version 1.48
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