Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Tested-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

The patch
fs/cifs: make share unaccessible at root level mountable
makes use of prepaths when any component of the underlying path is
inaccessible.

When mounting 2 separate shares having different prepaths but are other
wise similar in other respects, we end up sharing superblocks when we
shouldn't be doing so.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Tested-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Fix memory leaks introduced by the patch
fs/cifs: make share unaccessible at root level mountable

Also move allocation of cifs_sb->prepath to cifs_setup_cifs_sb().
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Tested-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

dentry->d_sb is just as good as parent->d_sb
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

During following a symbolic link we received err_buf from SMB2_open().
While the validity of SMB2 error response is checked previously
in smb2_check_message() a symbolic link payload is not checked at all.
Fix it by adding such checks.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

if, when mounting //HOST/share/sub/dir/foo we can query /sub/dir/foo but
not any of the path components above:

- store the /sub/dir/foo prefix in the cifs super_block info
- in the superblock, set root dentry to the subpath dentry (instead of
  the share root)
- set a flag in the superblock to remember it
- use prefixpath when building path from a dentry

fixes bso#8950
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Vladimir has noticed that we might declare memcg oom even during
readahead because read_pages only uses GFP_KERNEL (with mapping_gfp
restriction) while __do_page_cache_readahead uses
page_cache_alloc_readahead which adds __GFP_NORETRY to prevent from
OOMs.  This gfp mask discrepancy is really unfortunate and easily
fixable.  Drop page_cache_alloc_readahead() which only has one user and
outsource the gfp_mask logic into readahead_gfp_mask and propagate this
mask from __do_page_cache_readahead down to read_pages.

This alone would have only very limited impact as most filesystems are
implementing ->readpages and the common implementation mpage_readpages
does GFP_KERNEL (with mapping_gfp restriction) again.  We can tell it to
use readahead_gfp_mask instead as this function is called only during
readahead as well.  The same applies to read_cache_pages.

ext4 has its own ext4_mpage_readpages but the path which has pages !=
NULL can use the same gfp mask.  Btrfs, cifs, f2fs and orangefs are
doing a very similar pattern to mpage_readpages so the same can be
applied to them as well.

[akpm@linux-foundation.org: coding-style fixes]
[mhocko@suse.com: restrict gfp mask in mpage_alloc]
  Link: http://lkml.kernel.org/r/20160610074223.GC32285@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1465301556-26431-1-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Chris Mason <clm@fb.com>
Cc: Steve French <sfrench@samba.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Cc: Mike Marshall <hubcap@omnibond.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Changman Lee <cm224.lee@samsung.com>
Cc: Chao Yu <yuchao0@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The secmech hmac(md5) structures are present in the TCP_Server_Info
struct and can be shared among multiple CIFS sessions.  However, the
server mutex is not currently held when these structures are allocated
and used, which can lead to a kernel crashes, as in the scenario below:

mount.cifs(8) #1				mount.cifs(8) #2

Is secmech.sdeschmaccmd5 allocated?
// false

						Is secmech.sdeschmaccmd5 allocated?
						// false

secmech.hmacmd = crypto_alloc_shash..
secmech.sdeschmaccmd5 = kzalloc..
sdeschmaccmd5->shash.tfm = &secmec.hmacmd;

						secmech.sdeschmaccmd5 = kzalloc
						// sdeschmaccmd5->shash.tfm
						// not yet assigned

crypto_shash_update()
 deref NULL sdeschmaccmd5->shash.tfm

 Unable to handle kernel paging request at virtual address 00000030
 epc   : 8027ba34 crypto_shash_update+0x38/0x158
 ra    : 8020f2e8 setup_ntlmv2_rsp+0x4bc/0xa84
 Call Trace:
  crypto_shash_update+0x38/0x158
  setup_ntlmv2_rsp+0x4bc/0xa84
  build_ntlmssp_auth_blob+0xbc/0x34c
  sess_auth_rawntlmssp_authenticate+0xac/0x248
  CIFS_SessSetup+0xf0/0x178
  cifs_setup_session+0x4c/0x84
  cifs_get_smb_ses+0x2c8/0x314
  cifs_mount+0x38c/0x76c
  cifs_do_mount+0x98/0x440
  mount_fs+0x20/0xc0
  vfs_kern_mount+0x58/0x138
  do_mount+0x1e8/0xccc
  SyS_mount+0x88/0xd4
  syscall_common+0x30/0x54

Fix this by locking the srv_mutex around the code which uses these
hmac(md5) structures.  All the other secmech algos already have similar
locking.

Fixes: 95dc8dd1 ("Limit allocation of crypto mechanisms to dialect which requires")
Signed-off-by: NRabin Vincent <rabinv@axis.com>
Acked-by: NSachin Prabhu <sprabhu@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

adfeb3e0 ("cifs: Make echo interval tunable") added a comparison of
vol->echo_interval to server->echo_interval as a criterium to
match_server(), but:

 (1) A default value is set for server->echo_interval but not for
 vol->echo_interval, meaning these can never match if the echo_interval
 option is not specified.

 (2) vol->echo_interval is in seconds but server->echo_interval is in
 jiffies, meaning these can never match even if the echo_interval option
 is specified.

This broke TCP session reuse since match_server() can never return 1.
Fix it.

Fixes: adfeb3e0 ("cifs: Make echo interval tunable")
Signed-off-by: NRabin Vincent <rabinv@axis.com>
Acked-by: NSachin Prabhu <sprabhu@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

When opening a file with O_CREAT flag, check to see if the file opened
is an existing directory.

This prevents the directory from being opened which subsequently causes
a crash when the close function for directories cifs_closedir() is called
which frees up the file->private_data memory while the file is still
listed on the open file list for the tcon.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reported-by: NXiaoli Feng <xifeng@redhat.com>

We should be able to use the same helper functions used for SMB 2.1 and
later versions.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

->atomic_open() can be given an in-lookup dentry *or* a negative one
found in dcache.  Use d_in_lookup() to tell one from another, rather
than d_unhashed().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

POSIX allows files with trailing spaces or a trailing period but
SMB3 does not, so convert these using the normal Services For Mac
mapping as we do for other reserved characters such as
	: < > | ? *
This is similar to what Macs do for the same problem over SMB3.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <steve.french@primarydata.com>
Acked-by: NPavel Shilovsky <pshilovsky@samba.org>

Azure server blocks clients that open a socket and don't do anything on it.
In our reconnect scenarios, we can reconnect the tcp session and
detect the socket is available but we defer the negprot and SMB3 session
setup and tree connect reconnection until the next i/o is requested, but
this looks suspicous to some servers who expect SMB3 negprog and session
setup soon after a socket is created.

In the echo thread, reconnect SMB3 sessions and tree connections
that are disconnected.  A later patch will replay persistent (and
resilient) handle opens.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <steve.french@primarydata.com>
Acked-by: NPavel Shilovsky <pshilovsky@samba.org>

calc_lanman_hash() could return -ENOMEM or other errors, we should check
that everything went fine before using the calculated key.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

In sess_auth_rawntlmssp_authenticate(), the ntlmssp blob is allocated
statically and its size is an "empirical" 5*sizeof(struct
_AUTHENTICATE_MESSAGE) (320B on x86_64). I don't know where this value
comes from or if it was ever appropriate, but it is currently
insufficient: the user and domain name in UTF16 could take 1kB by
themselves. Because of that, build_ntlmssp_auth_blob() might corrupt
memory (out-of-bounds write). The size of ntlmssp_blob in
SMB2_sess_setup() is too small too (sizeof(struct _NEGOTIATE_MESSAGE)
+ 500).

This patch allocates the blob dynamically in
build_ntlmssp_auth_blob().
Signed-off-by: NJerome Marchand <jmarchan@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>

Currently in build_ntlmssp_auth_blob(), when converting the domain
name to UTF16, CIFS_MAX_USERNAME_LEN limit is used. It should be
CIFS_MAX_DOMAINNAME_LEN. This patch fixes this.
Signed-off-by: NJerome Marchand <jmarchan@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Right now, we send the tgid cross the wire. What we really want to send
though is a hashed fl_owner_t since samba treats this field as a generic
lockowner.

It turns out that because we enforce and release locks locally before
they are ever sent to the server, this patch makes no difference in
behavior. Still, setting OFD locks on the server using the process
pid seems wrong, so I think this patch still makes sense.
Signed-off-by: NJeff Layton <jlayton@poochiereds.net>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilovsky@samba.org>
Acked-by: NSachin Prabhu <sprabhu@redhat.com>

We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

it's not needed for file_operations of inodes located on fs defined
in the hosting module and for file_operations that go into procfs.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

preparation for similar switch in ->setxattr() (see the next commit for
rationale).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Remove some obsolete comments in the cifs inode_operations
structs that were pointed out by Stephen Rothwell.

CC: Stephen Rothwell <sfr@canb.auug.org.au>
CC: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <steve.french@primarydata.com>

The session key is the default keyring set for request_key operations.
This session key is revoked when the user owning the session logs out.
Any long running daemon processes started by this session ends up with
revoked session keyring which prevents these processes from using the
request_key mechanism from obtaining the krb5 keys.

The problem has been reported by a large number of autofs users. The
problem is also seen with multiuser mounts where the share may be used
by processes run by a user who has since logged out. A reproducer using
automount is available on the Red Hat bz.

The patch creates a new keyring which is used to cache cifs spnego
upcalls.

Red Hat bz: 1267754
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reported-by: NScott Mayhew <smayhew@redhat.com>
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Wrong return code was being returned on SMB3 rmdir of
non-empty directory.

For SMB3 (unlike for cifs), we attempt to delete a directory by
set of delete on close flag on the open. Windows clients set
this flag via a set info (SET_FILE_DISPOSITION to set this flag)
which properly checks if the directory is empty.

With this patch on smb3 mounts we correctly return
 "DIRECTORY NOT EMPTY"
on attempts to remove a non-empty directory.
Signed-off-by: NSteve French <steve.french@primarydata.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: NSachin Prabhu <sprabhu@redhat.com>

Signed-off-by: NSteven French <steve.french@primarydata.com>

Only server which map unknown users to guest will allow
access using a non-null NTLMv2_Response.

For Samba it's the "map to guest = bad user" option.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913Signed-off-by: NStefan Metzmacher <metze@samba.org>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Only server which map unknown users to guest will allow
access using a non-null NTChallengeResponse.

For Samba it's the "map to guest = bad user" option.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913Signed-off-by: NStefan Metzmacher <metze@samba.org>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Only server which map unknown users to guest will allow
access using a non-null LMChallengeResponse.

For Samba it's the "map to guest = bad user" option.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913Signed-off-by: NStefan Metzmacher <metze@samba.org>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

See [MS-NLMP] 3.2.5.1.2 Server Receives an AUTHENTICATE_MESSAGE from the Client:

   ...
   Set NullSession to FALSE
   If (AUTHENTICATE_MESSAGE.UserNameLen == 0 AND
      AUTHENTICATE_MESSAGE.NtChallengeResponse.Length == 0 AND
      (AUTHENTICATE_MESSAGE.LmChallengeResponse == Z(1)
       OR
       AUTHENTICATE_MESSAGE.LmChallengeResponse.Length == 0))
       -- Special case: client requested anonymous authentication
       Set NullSession to TRUE
   ...

Only server which map unknown users to guest will allow
access using a non-null NTChallengeResponse.

For Samba it's the "map to guest = bad user" option.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913

CC: Stable <stable@vger.kernel.org>
Signed-off-by: NStefan Metzmacher <metze@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

We currently do not check if any delimiter exists before the prefix
path in cifs_compose_mount_options(). Consequently when building the
devname using cifs_build_devname() we can end up with multiple
delimiters separating the UNC and the prefix path.

An issue was reported by the customer mounting a folder within a DFS
share from a Netapp server which uses McAfee antivirus. We have
narrowed down the cause to the use of double backslashes in the file
name used to open the file. This was determined to be caused because of
additional delimiters as a result of the bug.

In addition to changes in cifs_build_devname(), we also fix
cifs_parse_devname() to ignore any preceding delimiter for the prefix
path.

The problem was originally reported on RHEL 6 in RHEL bz 1252721. This
is the upstream version of the fix. The fix was confirmed by looking at
the packet capture of a DFS mount.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

CIFS may be used as lower layer of overlayfs and accessing f_path.dentry can
lead to a crash.

Fix by replacing direct access of file->f_path.dentry with the
file_dentry() accessor, which will always return a native object.
Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The kiocb already has the new position, so use that.  The only interesting
case is AIO, where we currently don't bother updating ki_pos.  We're about
to free the kiocb after we're done, so we might as well update it to make
everyone's life simpler.

While we're at it also return the bytes written argument passed in if
we were successful so that the boilerplate error switch code in the
callers can go away.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This will allow us to do per-I/O sync file writes, as required by a lot
of fileservers or storage targets.

XXX: Will need a few additional audits for O_DSYNC
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Including blkdev_direct_IO and dax_do_io.  It has to be ki_pos to actually
work, so eliminate the superflous argument.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use xattr handlers for resolving attribute names.  The amount of setup
code required on cifs is nontrivial, so use the same get and set
functions for all handlers, with switch statements for the different
types of attributes in them.

The set_EA handler can handle NULL values, so we don't need a separate
removexattr function anymore.  Remove the cifs_dbg statements related to
xattr name resolution; they don't add much.  Don't build xattr.o when
CONFIG_CIFS_XATTR is not defined.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If cifs_removexattr finds a "user." or "os2." xattr name prefix, it
skips 5 bytes, one byte too many for "os2.".
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The two values ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT are meant to be
enumerations, not bits in a bit mask.  Use '==' instead of '&' to check
for these values.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use strcmp(str, name) instead of strncmp(str, name, strlen(name)) for
checking if str and name are the same (as opposed to name being a prefix
of str) in the gexattr and setxattr inode operations.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>