linux-stable.git/fs/reiserfs, branch linux-3.9.y

reiserfs: fix spurious multiple-fill in reiserfs_readdir_dentry

2013-06-07T19:53:22+00:00

commit 0bdc7acba56a7ca4232f15f37b16f7ec079385ab upstream.

After sleeping for filldir(), we check to see if the file system has
changed and research. The next_pos pointer is updated but its value
isn't pushed into the key used for the search itself. As a result,
the search returns the same item that the last cycle of the loop did
and filldir() is called multiple times with the same data.

The end result is that the buffer can contain the same name multiple
times. This can be returned to userspace or used internally in the
xattr code where it can manifest with the following warning:

jdm-20004 reiserfs_delete_xattrs: Couldn't delete all xattrs (-2)

reiserfs_for_each_xattr uses reiserfs_readdir_dentry to iterate over
the xattr names and ends up trying to unlink the same name twice. The
second attempt fails with -ENOENT and the error is returned. At some
point I'll need to add support into reiserfsck to remove the orphaned
directories left behind when this occurs.

The fix is to push the value into the key before researching.

Signed-off-by: Jeff Mahoney 
Signed-off-by: Jan Kara 
Signed-off-by: Jonghwan Choi 
Signed-off-by: Greg Kroah-Hartman

reiserfs: fix problems with chowning setuid file w/ xattrs

2013-06-07T19:53:22+00:00

commit 4a8570112b76a63ad21cfcbe2783f98f7fd5ba1b upstream.

reiserfs_chown_xattrs() takes the iattr struct passed into ->setattr
and uses it to iterate over all the attrs associated with a file to change
ownership of xattrs (and transfer quota associated with the xattr files).

When the setuid bit is cleared during chown, ATTR_MODE and iattr->ia_mode
are passed to all the xattrs as well. This means that the xattr directory
will have S_IFREG added to its mode bits.

This has been prevented in practice by a missing IS_PRIVATE check
in reiserfs_acl_chmod, which caused a double-lock to occur while holding
the write lock. Since the file system was completely locked up, the
writeout of the corrupted mode never happened.

This patch temporarily clears everything but ATTR_UID|ATTR_GID for the
calls to reiserfs_setattr and adds the missing IS_PRIVATE check.

Signed-off-by: Jeff Mahoney 
Signed-off-by: Jan Kara 
Signed-off-by: Jonghwan Choi 
Signed-off-by: Greg Kroah-Hartman

reiserfs: fix deadlock with nfs racing on create/lookup

2013-06-07T19:53:22+00:00

commit a1457c0ce976bad1356b9b0437f2a5c3ab8a9cfc upstream.

Reiserfs is currently able to be deadlocked by having two NFS clients
where one has removed and recreated a file and another is accessing the
file with an open file handle.

If one client deletes and recreates a file with timing such that the
recreated file obtains the same [dirid, objectid] pair as the original
file while another client accesses the file via file handle, the create
and lookup can race and deadlock if the lookup manages to create the
in-memory inode first.

The create thread, in insert_inode_locked4, will hold the write lock
while waiting on the other inode to be unlocked. The lookup thread,
anywhere in the iget path, will release and reacquire the write lock while
it schedules. If it needs to reacquire the lock while the create thread
has it, it will never be able to make forward progress because it needs
to reacquire the lock before ultimately unlocking the inode.

This patch drops the write lock across the insert_inode_locked4 call so
that the ordering of inode_wait -> write lock is retained. Since this
would have been the case before the BKL push-down, this is safe.

Signed-off-by: Jeff Mahoney 
Signed-off-by: Jan Kara 
Signed-off-by: Jonghwan Choi 
Signed-off-by: Greg Kroah-Hartman

reiserfs: Fix warning and inode leak when deleting inode with xattrs

2013-03-29T16:08:43+00:00

After commit 21d8a15a (lookup_one_len: don't accept . and ..) reiserfs
started failing to delete xattrs from inode. This was due to a buggy
test for '.' and '..' in fill_with_dentries() which resulted in passing
'.' and '..' entries to lookup_one_len() in some cases. That returned
error and so we failed to iterate over all xattrs of and inode.

Fix the test in fill_with_dentries() along the lines of the one in
lookup_one_len().

Reported-by: Pawel Zawora 
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara

reiserfs: Use kstrdup instead of kmalloc/strcpy

2013-03-11T21:05:57+00:00

Signed-off-by: Ionut-Gabriel Radu 
Signed-off-by: Jan Kara

fs: Limit sys_mount to only request filesystem modules.

2013-03-04T03:36:31+00:00

Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn 
Acked-by: Kees Cook 
Reported-by: Kees Cook 
Signed-off-by: "Eric W. Biederman"

fs: encode_fh: return FILEID_INVALID if invalid fid_type

2013-02-26T07:46:10+00:00

This patch is a follow up on below patch:

[PATCH] exportfs: add FILEID_INVALID to indicate invalid fid_type
commit: 216b6cbdcbd86b1db0754d58886b466ae31f5a63

Signed-off-by: Namjae Jeon 
Signed-off-by: Vivek Trivedi 
Acked-by: Steven Whitehouse 
Acked-by: Sage Weil 
Signed-off-by: Al Viro

new helper: file_inode(file)

2013-02-23T04:31:31+00:00

Signed-off-by: Al Viro

reiserfs: drop vmtruncate

2012-12-20T19:00:01+00:00

Removed vmtruncate

Signed-off-by: Marco Stornelli 
Reviewed-by: Jan Kara 
Signed-off-by: Al Viro

reiserfs: Move quota calls out of write lock

2012-11-19T20:34:33+00:00

Calls into highlevel quota code cannot happen under the write lock. These
calls take dqio_mutex which ranks above write lock. So drop write lock
before calling back into quota code.

CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara