CIFS: attempt to fix kernel bugzilla 215375

CIFS: attempt to fix kernel bugzilla 215375

[Ronnie Sahlberg]

Steve, 
Here is an attempt to fix kernel bz 215375.
I can not test it, since I don't have access to servers this old but the change
should be safe for modern users as it only affects the password field for
"share mode" security, which we do not support anyway.

It is only tested for regressions with user mode security on win98 and later systems, using ntlmssp
authentication.

[PATCH] cifs: fix buf in smb1 tree connect where we mount a share without suer security

[Ronnie Sahlberg]

Unconditionally alway set an empty password (length 1) for SMB1 Tree Connect password.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/connect.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 3da5da9f16b0..cab1be85dfa4 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3926,12 +3926,11 @@ CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
 	pSMB->AndXCommand = 0xFF;
 	pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
 	bcc_ptr = &pSMB->Password[0];
-	if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
-		pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
-		*bcc_ptr = 0; /* password is null byte */
-		bcc_ptr++;              /* skip password */
-		/* already aligned so no need to do it below */
-	}
+
+	pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
+	*bcc_ptr = 0; /* password is null byte */
+	bcc_ptr++;              /* skip password */
+	/* already aligned so no need to do it below */
 
 	if (ses->server->sign)
 		smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
-- 
2.35.3

Re: CIFS: attempt to fix kernel bugzilla 215375

[Steve French]

Any thoughts about setting up VMs for Win98 to try this?  Any luck
trying to test with the fix?

On Tue, Sep 6, 2022 at 12:42 AM Ronnie Sahlberg <lsahlber@redhat.com> wrote:
>
> Steve,
> Here is an attempt to fix kernel bz 215375.
> I can not test it, since I don't have access to servers this old but the change
> should be safe for modern users as it only affects the password field for
> "share mode" security, which we do not support anyway.
>
> It is only tested for regressions with user mode security on win98 and later systems, using ntlmssp
> authentication.
>
>
>


-- 
Thanks,

Steve

Re: CIFS: attempt to fix kernel bugzilla 215375

[Thorsten Leemhuis]

On 10.09.22 17:19, Steve French wrote:
> Any thoughts about setting up VMs for Win98 to try this?  Any luck
> trying to test with the fix?

Ronnie, Steve, any news on that patch and a way forward? More and more
users are showing up in
https://bugzilla.kernel.org/show_bug.cgi?id=215375 and complain about
this regression. :-/ At least one of them apparently tested the patch
now successfully: https://bugzilla.kernel.org/show_bug.cgi?id=215375#c43

Ciao, Thorsten

> On Tue, Sep 6, 2022 at 12:42 AM Ronnie Sahlberg <lsahlber@redhat.com> wrote:
>>
>> Steve,
>> Here is an attempt to fix kernel bz 215375.
>> I can not test it, since I don't have access to servers this old but the change
>> should be safe for modern users as it only affects the password field for
>> "share mode" security, which we do not support anyway.
>>
>> It is only tested for regressions with user mode security on win98 and later systems, using ntlmssp
>> authentication.
>>
>>
>>
> 
>