linux-toradex.git/fs, branch v4.2.1

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

ocfs2: direct write will call ocfs2_rw_unlock() twice when doing aio+dio

2015-09-21T17:10:59+00:00

commit aa1057b3dec478b20c77bad07442318ae36d893c upstream.

ocfs2_file_write_iter() is usng the wrong return value ('written').  This
will cause ocfs2_rw_unlock() be called both in write_iter & end_io,
triggering a BUG_ON.

This issue was introduced by commit 7da839c47589 ("ocfs2: use
__generic_file_write_iter()").

Orabug: 21612107
Fixes: 7da839c47589 ("ocfs2: use __generic_file_write_iter()")
Signed-off-by: Ryan Ding 
Reviewed-by: Junxiao Bi 
Cc: Al Viro 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

hpfs: update ctime and mtime on directory modification

2015-09-21T17:10:59+00:00

commit f49a26e7718dd30b49e3541e3e25aecf5e7294e2 upstream.

Update ctime and mtime when a directory is modified. (though OS/2 doesn't
update them anyway)

Signed-off-by: Mikulas Patocka 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fs: Set the size of empty dirs to 0.

2015-09-21T17:10:59+00:00

commit 4b75de8615050c1b0dd8d7794838c42f74ed36ba upstream.

Before the make_empty_dir_inode calls were introduce into proc, sysfs,
and sysctl those directories when stated reported an i_size of 0.
make_empty_dir_inode started reporting an i_size of 2.  At least one
userspace application depended on stat returning i_size of 0.  So
modify make_empty_dir_inode to cause an i_size of 0 to be reported for
these directories.

Reported-by: Tejun Heo 
Acked-by: Tejun Heo 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

xfs: return errors from partial I/O failures to files

2015-09-21T17:10:52+00:00

commit c9eb256eda4420c06bb10f5e8fbdbe1a34bc98e0 upstream.

There is an issue with xfs's error reporting in some cases of I/O partially
failing and partially succeeding. Calls like fsync() can report success even
though not all I/O was successful in partial-failure cases such as one disk of
a RAID0 array being offline.

The issue can occur when there are more than one bio per xfs_ioend struct.
Each call to xfs_end_bio() for a bio completing will write a value to
ioend->io_error.  If a successful bio completes after any failed bio, no
error is reported do to it writing 0 over the error code set by any failed bio.
The I/O error information is now lost and when the ioend is completed
only success is reported back up the filesystem stack.

xfs_end_bio() should only set ioend->io_error in the case of BIO_UPTODATE
being clear.  ioend->io_error is initialized to 0 at allocation so only needs
to be updated by a failed bio. Also check that ioend->io_error is 0 so that
the first error reported will be the error code returned.

Signed-off-by: David Jeffery 
Reviewed-by: Dave Chinner 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman

xfs: Fix file type directory corruption for btree directories

2015-09-21T17:10:51+00:00

commit 037542345a82aaaa228ec280fe6ddff1568d169f upstream.

Users have occasionally reported that file type for some directory
entries is wrong. This mostly happened after updating libraries some
libraries. After some debugging the problem was traced down to
xfs_dir2_node_replace(). The function uses args->filetype as a file type
to store in the replaced directory entry however it also calls
xfs_da3_node_lookup_int() which will store file type of the current
directory entry in args->filetype. Thus we fail to change file type of a
directory entry to a proper type.

Fix the problem by storing new file type in a local variable before
calling xfs_da3_node_lookup_int().

Reported-by: Giacomo Comes 
Signed-off-by: Jan Kara 
Reviewed-by: Dave Chinner 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman

xfs: Fix xfs_attr_leafblock definition

2015-09-21T17:10:51+00:00

commit ffeecc5213024ae663377b442eedcfbacf6d0c5d upstream.

struct xfs_attr_leafblock contains 'entries' array which is declared
with size 1 altough it can in fact contain much more entries. Since this
array is followed by further struct members, gcc (at least in version
4.8.3) thinks that the array has the fixed size of 1 element and thus
may optimize away all accesses beyond the end of array resulting in
non-working code. This problem was only observed with userspace code in
xfsprogs, however it's better to be safe in kernel as well and have
matching kernel and xfsprogs definitions.

Signed-off-by: Jan Kara 
Reviewed-by: Dave Chinner 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman

libxfs: readahead of dir3 data blocks should use the read verifier

2015-09-21T17:10:51+00:00

commit 2f123bce18943fff819bc10f8868ffb9149fc622 upstream.

In the dir3 data block readahead function, use the regular read
verifier to check the block's CRC and spot-check the block contents
instead of directly calling only the spot-checking routine.  This
prevents corrupted directory data blocks from being read into the
kernel, which can lead to garbage ls output and directory loops (if
say one of the entries contains slashes and other junk).

Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman

writeback: sync_inodes_sb() must write out I_DIRTY_TIME inodes and always call wait_sb_inodes()

2015-08-25T20:35:09+00:00

e79729123f63 ("writeback: don't issue wb_writeback_work if clean")
updated writeback path to avoid kicking writeback work items if there
are no inodes to be written out; unfortunately, the avoidance logic
was too aggressive and broke sync_inodes_sb().

* sync_inodes_sb() must write out I_DIRTY_TIME inodes but I_DIRTY_TIME
  inodes dont't contribute to bdi/wb_has_dirty_io() tests and were
  being skipped over.

* inodes are taken off wb->b_dirty/io/more_io lists after writeback
  starts on them.  sync_inodes_sb() skipping wait_sb_inodes() when
  bdi_has_dirty_io() breaks it by making it return while writebacks
  are in-flight.

This patch fixes the breakages by

* Removing bdi_has_dirty_io() shortcut from bdi_split_work_to_wbs().
  The callers are already testing the condition.

* Removing bdi_has_dirty_io() shortcut from sync_inodes_sb() so that
  it always calls into bdi_split_work_to_wbs() and wait_sb_inodes().

* Making bdi_split_work_to_wbs() consider the b_dirty_time list for
  WB_SYNC_ALL writebacks.

Kudos to Eryu, Dave and Jan for tracking down the issue.

Signed-off-by: Tejun Heo 
Fixes: e79729123f63 ("writeback: don't issue wb_writeback_work if clean")
Link: http://lkml.kernel.org/g/20150812101204.GE17933@dhcp-13-216.nay.redhat.com
Reported-and-bisected-by: Eryu Guan 
Cc: Dave Chinner 
Cc: Jan Kara 
Cc: Ted Ts'o 
Signed-off-by: Jens Axboe

fs/fuse: fix ioctl type confusion

2015-08-16T19:35:44+00:00

fuse_dev_ioctl() performed fuse_get_dev() on a user-supplied fd,
leading to a type confusion issue. Fix it by checking file->f_op.

Signed-off-by: Jann Horn 
Acked-by: Miklos Szeredi 
Signed-off-by: Linus Torvalds