linux-stable.git/fs/cifs, branch linux-3.13.y

CIFS: Fix too big maxBuf size for SMB3 mounts

2014-03-07T06:06:10+00:00

commit 2365c4eaf077c48574ab6f143960048fc0f31518 upstream.

SMB3 servers can respond with MaxTransactSize of more than 4M
that can cause a memory allocation error returned from kmalloc
in a lock codepath. Also the client doesn't support multicredit
requests now and allows buffer sizes of 65536 bytes only. Set
MaxTransactSize to this maximum supported value.

Signed-off-by: Pavel Shilovsky 
Acked-by: Jeff Layton 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

cifs: ensure that uncached writes handle unmapped areas correctly

2014-03-07T06:06:10+00:00

commit 5d81de8e8667da7135d3a32a964087c0faf5483f upstream.

It's possible for userland to pass down an iovec via writev() that has a
bogus user pointer in it. If that happens and we're doing an uncached
write, then we can end up getting less bytes than we expect from the
call to iov_iter_copy_from_user. This is CVE-2014-0069

cifs_iovec_write isn't set up to handle that situation however. It'll
blindly keep chugging through the page array and not filling those pages
with anything useful. Worse yet, we'll later end up with a negative
number in wdata->tailsz, which will confuse the sending routines and
cause an oops at the very least.

Fix this by having the copy phase of cifs_iovec_write stop copying data
in this situation and send the last write as a short one. At the same
time, we want to avoid sending a zero-length write to the server, so
break out of the loop and set rc to -EFAULT if that happens. This also
allows us to handle the case where no address in the iovec is valid.

[Note: Marking this for stable on v3.4+ kernels, but kernels as old as
       v2.6.38 may have a similar problem and may need similar fix]

Reviewed-by: Pavel Shilovsky 
Reported-by: Al Viro 
Signed-off-by: Jeff Layton 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

retrieving CIFS ACLs when mounted with SMB2 fails dropping session

2014-02-22T21:34:42+00:00

commit 83e3bc23ef9ce7c03b7b4e5d3d790246ea59db3e upstream.

The get/set ACL xattr support for CIFS ACLs attempts to send old
cifs dialect protocol requests even when mounted with SMB2 or later
dialects. Sending cifs requests on an smb2 session causes problems -
the server drops the session due to the illegal request.

This patch makes CIFS ACL operations protocol specific to fix that.

Attempting to query/set CIFS ACLs for SMB2 will now return
EOPNOTSUPP (until we add worker routines for sending query
ACL requests via SMB2) instead of sending invalid (cifs)
requests.

A separate followon patch will be needed to fix cifs_acl_to_fattr
(which takes a cifs specific u16 fid so can't be abstracted
to work with SMB2 until that is changed) and will be needed
to fix mount problems when "cifsacl" is specified on mount
with e.g. vers=2.1

Signed-off-by: Steve French 
Reviewed-by: Shirish Pargaonkar 
Signed-off-by: Greg Kroah-Hartman

Add protocol specific operation for CIFS xattrs

2014-02-22T21:34:41+00:00

commit d979f3b0a1f0b5499ab85e68cdf02b56852918b6 upstream.

Changeset 666753c3ef8fc88b0ddd5be4865d0aa66428ac35 added protocol
operations for get/setxattr to avoid calling cifs operations
on smb2/smb3 mounts for xattr operations and this changeset
adds the calls to cifs specific protocol operations for xattrs
(in order to reenable cifs support for xattrs which was
temporarily disabled by the previous changeset.  We do not
have SMB2/SMB3 worker function for setting xattrs yet so
this only enables it for cifs.

CCing stable since without these two small changsets (its
small coreq 666753c3ef8fc88b0ddd5be4865d0aa66428ac35 is
also needed) calling getfattr/setfattr on smb2/smb3 mounts
causes problems.

Signed-off-by: Steve French 
Reviewed-by: Shirish Pargaonkar 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix SMB2 mounts so they don't try to set or get xattrs via cifs

2014-02-22T21:34:41+00:00

commit 666753c3ef8fc88b0ddd5be4865d0aa66428ac35 upstream.

When mounting with smb2 (or smb2.1 or smb3) we need to check to make
sure that attempts to query or set extended attributes do not
attempt to send the request with the older cifs protocol instead
(eventually we also need to add the support in SMB2
to query/set extended attributes but this patch prevents us from
using the wrong protocol for extended attribute operations).

Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

cifs: set FILE_CREATED

2013-12-27T21:14:45+00:00

Set FILE_CREATED on O_CREAT|O_EXCL.

cifs code didn't change during commit 116cc0225381415b96551f725455d067f63a76a0

Kernel bugzilla 66251

Signed-off-by: Shirish Pargaonkar 
Acked-by: Jeff Layton 
CC: Stable 
Signed-off-by: Steve French

cifs: We do not drop reference to tlink in CIFSCheckMFSymlink()

2013-12-27T21:14:44+00:00

When we obtain tcon from cifs_sb, we use cifs_sb_tlink() to first obtain
tlink which also grabs a reference to it. We do not drop this reference
to tlink once we are done with the call.

The patch fixes this issue by instead passing tcon as a parameter and
avoids having to obtain a reference to the tlink. A lookup for the tcon
is already made in the calling functions and this way we avoid having to
re-run the lookup. This is also consistent with the argument list for
other similar calls for M-F symlinks.

We should also return an ENOSYS when we do not find a protocol specific
function to lookup the MF Symlink data.

Signed-off-by: Sachin Prabhu 
Reviewed-by: Jeff Layton 
CC: Stable 
Signed-off-by: Steve French

Add missing end of line termination to some cifs messages

2013-12-27T21:14:44+00:00

Signed-off-by: Steve French 
Signed-off-by: Gregor Beck 
Reviewed-by: Jeff Layton

[CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload

2013-11-25T15:50:31+00:00

Change cifs.ko to using CIFS_IOCTL_COPYCHUNK instead
of BTRFS_IOC_CLONE to avoid confusion about whether
copy-on-write is required or optional for this operation.

SMB2/SMB3 copyoffload had used the BTRFS_IOC_CLONE ioctl since
they both speed up copy by offloading the copy rather than
passing many read and write requests back and forth and both have
identical syntax (passing file handles), but for SMB2/SMB3
CopyChunk the server is not required to use copy-on-write
to make a copy of the file (although some do), and Christoph
has commented that since CopyChunk does not require
copy-on-write we should not reuse BTRFS_IOC_CLONE.

This patch renames the ioctl to use a cifs specific IOCTL
CIFS_IOCTL_COPYCHUNK.  This ioctl is particularly important
for SMB2/SMB3 since large file copy over the network otherwise
can be very slow, and with this is often more than 100 times
faster putting less load on server and client.

Note that if a copy syscall is ever introduced, depending on
its requirements/format it could end up using one of the other
three methods that CIFS/SMB2/SMB3 can do for copy offload,
but this method is particularly useful for file copy
and broadly supported (not just by Samba server).

Signed-off-by: Steve French 
Reviewed-by: Jeff Layton 
Reviewed-by: David Disseldorp

Check SMB3 dialects against downgrade attacks

2013-11-20T05:52:54+00:00

When we are running SMB3 or SMB3.02 connections which are signed
we need to validate the protocol negotiation information,
to ensure that the negotiate protocol response was not tampered with.

Add the missing FSCTL which is sent at mount time (immediately after
the SMB3 Tree Connect) to validate that the capabilities match
what we think the server sent.

"Secure dialect negotiation is introduced in SMB3 to protect against
man-in-the-middle attempt to downgrade dialect negotiation.
The idea is to prevent an eavesdropper from downgrading the initially
negotiated dialect and capabilities between the client and the server."

For more explanation see 2.2.31.4 of MS-SMB2 or
http://blogs.msdn.com/b/openspecification/archive/2012/06/28/smb3-secure-dialect-negotiation.aspx

Reviewed-by: Pavel Shilovsky 
Signed-off-by: Steve French