linux-stable.git/fs/ncpfs, branch linux-3.12.y

move d_rcu from overlapping d_child to overlapping d_alias

2015-01-29T14:45:16+00:00

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro 
Acked-by: Miklos Szeredi 
Signed-off-by: Jiri Slaby

ncpfs: return proper error from NCP_IOC_SETROOT ioctl

2015-01-07T16:55:17+00:00

commit a682e9c28cac152e6e54c39efcf046e0c8cfcf63 upstream.

If some error happens in NCP_IOC_SETROOT ioctl, the appropriate error
return value is then (in most cases) just overwritten before we return.
This can result in reporting success to userspace although error happened.

This bug was introduced by commit 2e54eb96e2c8 ("BKL: Remove BKL from
ncpfs").  Propagate the errors correctly.

Coverity id: 1226925.

Fixes: 2e54eb96e2c80 ("BKL: Remove BKL from ncpfs")
Signed-off-by: Jan Kara 
Cc: Petr Vandrovec 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Jiri Slaby

ncpfs: fix error return code in ncp_parse_options()

2013-07-08T09:36:43+00:00

Fix to return -EINVAL from the option parse error handling
case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun 
Signed-off-by: Al Viro

ncpfs: use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFT

2013-07-03T23:07:26+00:00

(*->vm_end - *->vm_start) >> PAGE_SHIFT operation is implemented
as a inline funcion vma_pages() in linux/mm.h, so using it.

Signed-off-by: Libin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29T08:57:36+00:00

Instances either don't look at it at all (the majority of cases) or
only want it to find the superblock (which can be had as dentry->d_sb).
A few cases that want more are actually safe with dentry->d_inode -
the only precaution needed is the check that it hadn't been replaced with
NULL by rmdir() or by overwriting rename(), which case should be simply
treated as cache miss.

Signed-off-by: Linus Torvalds 
Signed-off-by: Al Viro

kill find_inode_number()

2013-06-29T08:57:20+00:00

the only remaining caller (in ncpfs) is guaranteed to return 0 -
we only hit it if we'd just checked that there's no dentry with
such name.

Signed-off-by: Al Viro

ncpfs: don't bother with EBUSY on removal of busy directories

2013-06-29T08:57:16+00:00

Signed-off-by: Al Viro

[readdir] convert ncpfs

2013-06-29T08:56:57+00:00

Signed-off-by: Al Viro

ncpfs: fix rmdir returns Device or resource busy

2013-06-07T16:15:38+00:00

1d2ef5901483004d74947bbf78d5146c24038fe7 caused a regression in ncpfs such that
directories could no longer be removed.  This was because ncp_rmdir checked
to see if a dentry could be unhashed before allowing it to be removed. Since
1d2ef5901483004d74947bbf78d5146c24038fe7 introduced a change that incremented
dentry->d_count causing it to always be greater than 1 unhash would always
fail.  Thus causing the error path in ncp_rmdir to always be taken.  Removing
this error path is safe as unhashing is still accomplished by calls to dput
from vfs_rmdir.

Signed-off-by: Dave Chiluk 
Signed-off-by: Petr Vandrovec 
Signed-off-by: Al Viro

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"