linux-stable.git/fs/cifs, branch linux-3.4.y

cifs: use server timestamp for ntlmv2 authentication

2016-04-27T10:55:24+00:00

commit 98ce94c8df762d413b3ecb849e2b966b21606d04 upstream.

Linux cifs mount with ntlmssp against an Mac OS X (Yosemite
10.10.5) share fails in case the clocks differ more than +/-2h:

digest-service: digest-request: od failed with 2 proto=ntlmv2
digest-service: digest-request: kdc failed with -1561745592 proto=ntlmv2

Fix this by (re-)using the given server timestamp for the
ntlmv2 authentication (as Windows 7 does).

A related problem was also reported earlier by Namjae Jaen (see below):

Windows machine has extended security feature which refuse to allow
authentication when there is time difference between server time and
client time when ntlmv2 negotiation is used. This problem is prevalent
in embedded enviornment where system time is set to default 1970.

Modern servers send the server timestamp in the TargetInfo Av_Pair
structure in the challenge message [see MS-NLMP 2.2.2.1]
In [MS-NLMP 3.1.5.1.2] it is explicitly mentioned that the client must
use the server provided timestamp if present OR current time if it is
not

Reported-by: Namjae Jeon 
Signed-off-by: Peter Seiderer 
Signed-off-by: Steve French 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

fs: create and use seq_show_option for escaping

2016-04-27T10:55:18+00:00

commit a068acf2ee77693e0bf39d6e07139ba704f461c3 upstream.

Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g.  new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files.  This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else.  This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.

Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink).  Imagine the use
of "sudo" is something more sneaky:

  $ BASE="ovl"
  $ MNT="$BASE/mnt"
  $ LOW="$BASE/lower"
  $ UP="$BASE/upper"
  $ WORK="$BASE/work/ 0 0
  none /proc fuse.pwn user_id=1000"
  $ mkdir -p "$LOW" "$UP" "$WORK"
  $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt
  $ cat /proc/mounts
  none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0
  none /proc fuse.pwn user_id=1000 0 0
  $ fusermount -u /proc
  $ cat /proc/mounts
  cat: /proc/mounts: No such file or directory

This fixes the problem by adding new seq_show_option and
seq_show_option_n helpers, and updating the vulnerable show_option
handlers to use them as needed.  Some, like SELinux, need to be open
coded due to unusual existing escape mechanisms.

[akpm@linux-foundation.org: add lost chunk, per Kees]
[keescook@chromium.org: seq_show_option should be using const parameters]
Signed-off-by: Kees Cook 
Acked-by: Serge Hallyn 
Acked-by: Jan Kara 
Acked-by: Paul Moore 
Cc: J. R. Okajima 
Signed-off-by: Kees Cook 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[lizf: Backported to 3.4:
 - adjust context
 - one more place in ceph needs to be changed
 - drop changes to overlayfs
 - drop showing vers in cifs]
Signed-off-by: Zefan Li

cifs: fix use-after-free bug in find_writable_file

2015-06-19T03:40:30+00:00

commit e1e9bda22d7ddf88515e8fe401887e313922823e upstream.

Under intermittent network outages, find_writable_file() is susceptible
to the following race condition, which results in a user-after-free in
the cifs_writepages code-path:

Thread 1                                        Thread 2
========                                        ========

inv_file = NULL
refind = 0
spin_lock(&cifs_file_list_lock)

// invalidHandle found on openFileList

inv_file = open_file
// inv_file->count currently 1

cifsFileInfo_get(inv_file)
// inv_file->count = 2

spin_unlock(&cifs_file_list_lock);

cifs_reopen_file()                            cifs_close()
// fails (rc != 0)                            ->cifsFileInfo_put()
                                       spin_lock(&cifs_file_list_lock)
                                       // inv_file->count = 1
                                       spin_unlock(&cifs_file_list_lock)

spin_lock(&cifs_file_list_lock);
list_move_tail(&inv_file->flist,
      &cifs_inode->openFileList);
spin_unlock(&cifs_file_list_lock);

cifsFileInfo_put(inv_file);
->spin_lock(&cifs_file_list_lock)

  // inv_file->count = 0
  list_del(&cifs_file->flist);
  // cleanup!!
  kfree(cifs_file);

  spin_unlock(&cifs_file_list_lock);

spin_lock(&cifs_file_list_lock);
++refind;
// refind = 1
goto refind_writable;

At this point we loop back through with an invalid inv_file pointer
and a refind value of 1. On second pass, inv_file is not overwritten on
openFileList traversal, and is subsequently dereferenced.

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

move d_rcu from overlapping d_child to overlapping d_alias

2015-04-14T09:33:58+00:00

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro 
[bwh: Backported to 3.2:
 - Apply name changes in all the different places we use d_alias and d_child
 - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()]
Signed-off-by: Ben Hutchings 
[lizf: Backported to 3.4:
 - adjust context
 - need one more name change in debugfs]

CIFS: Fix wrong directory attributes after rename

2014-09-25T03:49:11+00:00

commit b46799a8f28c43c5264ac8d8ffa28b311b557e03 upstream.

When we requests rename we also need to update attributes
of both source and target parent directories. Not doing it
causes generic/309 xfstest to fail on SMB2 mounts. Fix this
by marking these directories for force revalidating.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Zefan Li

CIFS: fix mount failure with broken pathnames when smb3 mount with mapchars option

2014-07-09T17:51:20+00:00

commit ce36d9ab3bab06b7b5522f5c8b68fac231b76ffb upstream.

When we SMB3 mounted with mapchars (to allow reserved characters : \ / > < * ?
via the Unicode Windows to POSIX remap range) empty paths
(eg when we open "" to query the root of the SMB3 directory on mount) were not
null terminated so we sent garbarge as a path name on empty paths which caused
SMB2/SMB2.1/SMB3 mounts to fail when mapchars was specified.  mapchars is
particularly important since Unix Extensions for SMB3 are not supported (yet)

Signed-off-by: Steve French 
Reviewed-by: David Disseldorp 
Signed-off-by: Greg Kroah-Hartman

cifs: delay super block destruction until all cifsFileInfo objects are gone

2014-06-07T23:02:04+00:00

commit 24261fc23db950951760d00c188ba63cc756b932 upstream.

cifsFileInfo objects hold references to dentries and it is possible that
these will still be around in workqueues when VFS decides to kill super
block during unmount.

This results in panics like this one:
BUG: Dentry ffff88001f5e76c0{i=66b4a,n=1M-2} still in use (1) [unmount of cifs cifs]
------------[ cut here ]------------
kernel BUG at fs/dcache.c:943!
[..]
Process umount (pid: 1781, threadinfo ffff88003d6e8000, task ffff880035eeaec0)
[..]
Call Trace:
 [] shrink_dcache_for_umount+0x33/0x60
 [] generic_shutdown_super+0x2c/0xe0
 [] kill_anon_super+0x16/0x30
 [] cifs_kill_sb+0x1a/0x30 [cifs]
 [] deactivate_locked_super+0x57/0x80
 [] deactivate_super+0x4e/0x70
 [] mntput_no_expire+0xd7/0x130
 [] sys_umount+0x9c/0x3c0
 [] system_call_fastpath+0x16/0x1b

Fix this by making each cifsFileInfo object hold a reference to cifs
super block, which implicitly keeps VFS super block around as well.

Signed-off-by: Mateusz Guzik 
Reviewed-by: Jeff Layton 
Reported-and-Tested-by: Ben Greear 
Signed-off-by: Steve French 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
[xr: Backported to 3.4: adjust context]
Signed-off-by: Rui Xiang 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix error handling in cifs_push_mandatory_locks

2014-06-07T23:02:03+00:00

commit e2f2886a824ff0a56da1eaa13019fde86aa89fa6 upstream.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
Cc: Rui Xiang 
Signed-off-by: Greg Kroah-Hartman

setfacl removes part of ACL when setting POSIX ACLs to Samba

2014-06-07T23:02:03+00:00

commit b1d93356427be6f050dc55c86eb019d173700af6 upstream.

setfacl over cifs mounts can remove the default ACL when setting the
(non-default part of) the ACL and vice versa (we were leaving at 0
rather than setting to -1 the count field for the unaffected
half of the ACL.  For example notice the setfacl removed
the default ACL in this sequence:

steven@steven-GA-970A-DS3:~/cifs-2.6$ getfacl /mnt/test-dir ; setfacl
-m default:user:test:rwx,user:test:rwx /mnt/test-dir
getfacl: Removing leading '/' from absolute path names
user::rwx
group::r-x
other::r-x
default:user::rwx
default:user:test:rwx
default:group::r-x
default:mask::rwx
default:other::r-x

steven@steven-GA-970A-DS3:~/cifs-2.6$ getfacl /mnt/test-dir
getfacl: Removing leading '/' from absolute path names
user::rwx
user:test:rwx
group::r-x
mask::rwx
other::r-x

Signed-off-by: Steve French 
Acked-by: Jeremy Allison 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
Cc: Rui Xiang 
Signed-off-by: Greg Kroah-Hartman

cifs: adjust sequence number downward after signing NT_CANCEL request

2014-03-11T23:10:05+00:00

commit 31efee60f489c759c341454d755a9fd13de8c03d upstream.

When a call goes out, the signing code adjusts the sequence number
upward by two to account for the request and the response. An NT_CANCEL
however doesn't get a response of its own, it just hurries the server
along to get it to respond to the original request more quickly.
Therefore, we must adjust the sequence number back down by one after
signing a NT_CANCEL request.

Reported-by: Tim Perry 
Signed-off-by: Jeff Layton 
Signed-off-by: Steve French 
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings 
Cc: Rui Xiang 
Signed-off-by: Greg Kroah-Hartman