linux-toradex.git/fs/cifs, branch v4.2.3

CIFS: fix type confusion in copy offload ioctl

2015-09-29T17:33:25+00:00

commit 4c17a6d56bb0cad3066a714e94f7185a24b40f49 upstream.

This might lead to local privilege escalation (code execution as
kernel) for systems where the following conditions are met:

 - CONFIG_CIFS_SMB2 and CONFIG_CIFS_POSIX are enabled
 - a cifs filesystem is mounted where:
  - the mount option "vers" was used and set to a value >=2.0
  - the attacker has write access to at least one file on the filesystem

To attack this, an attacker would have to guess the target_tcon
pointer (but guessing wrong doesn't cause a crash, it just returns an
error code) and win a narrow race.

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

fs: create and use seq_show_option for escaping

2015-09-21T17:10:59+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 
Signed-off-by: Greg Kroah-Hartman

cifs: Unset CIFS_MOUNT_POSIX_PATHS flag when following dfs mounts

2015-06-29T19:50:22+00:00

In a dfs setup where the client transitions from a server which supports
posix paths to a server which doesn't support posix paths, the flag
CIFS_MOUNT_POSIX_PATHS is not reset. This leads to the wrong directory
separator being used causing smb commands to fail.

Consider the following case where a dfs share on a samba server points
to a share on windows smb server.
 # mount -t cifs -o .. //vm140-31/dfsroot/testwin/
 # ls -l /mnt; touch /mnt/a
 total 0
 touch: cannot touch ‘/mnt/a’: No such file or directory

Signed-off-by: Sachin Prabhu 
Acked-by: Jeff Layton 
Signed-off-by: Steve French

Update negotiate protocol for SMB3.11 dialect

2015-06-29T02:15:48+00:00

Send negotiate contexts when SMB3.11 dialect is negotiated
(ie the preauth and the encryption contexts) and
Initialize SMB3.11 preauth negotiate context salt to random bytes

Followon patch will update session setup and tree connect

Signed-off-by: Steve French

Add ioctl to set integrity

2015-06-29T02:15:45+00:00

set integrity increases reliability of files stored on SMB3 servers.
Add ioctl to allow setting this on files on SMB3 and later mounts.

Signed-off-by: Steve French

Add Get/Set Integrity Information structure definitions

2015-06-29T02:15:41+00:00

Signed-off-by: Steve French

Add reflink copy over SMB3.11 with new FSCTL_DUPLICATE_EXTENTS

2015-06-29T02:15:38+00:00

 Getting fantastic copy performance with cp --reflink over SMB3.11
 using the new FSCTL_DUPLICATE_EXTENTS.

 This FSCTL was added in the SMB3.11 dialect (testing was
 against REFS file system) so have put it as a 3.11 protocol
 specific operation ("vers=3.1.1" on the mount).  Tested at
 the SMB3 plugfest in Redmond.

 It depends on the new FS Attribute (BLOCK_REFCOUNTING) which
 is used to advertise support for the ability to do this ioctl
 (if you can support multiple files pointing to the same block
 than this refcounting ability or equivalent is needed to
 support the new reflink-like duplicate extent SMB3 ioctl.

Signed-off-by: Steve French

Add SMB3.11 mount option synonym for new dialect

2015-06-28T03:28:11+00:00

Most people think of SMB 3.1.1 as SMB version 3.11 so add synonym
for "vers=3.1.1" of "vers=3.11" on mount.

Also make sure that unlike SMB3.0 and 3.02 we don't send
validate negotiate on mount (it is handled by negotiate contexts) -
add list of SMB3.11 specific functions (distinct from 3.0 dialect).

Signed-off-by: Steve French w

add struct FILE_STANDARD_INFO

2015-06-28T03:25:56+00:00

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

Make dialect negotiation warning message easier to read

2015-06-28T03:28:49+00:00

Dialect version and minor version are easier to read in hex

Signed-off-by: Steve French