linux-toradex.git/fs/btrfs/ioctl.c, branch v3.12.11

btrfs: restrict snapshotting to own subvolumes

2014-02-06T19:22:22+00:00

commit d024206133ce21936b3d5780359afc00247655b7 upstream.

Currently, any user can snapshot any subvolume if the path is accessible and
thus indirectly create and keep files he does not own under his direcotries.
This is not possible with traditional directories.

In security context, a user can snapshot root filesystem and pin any
potentially buggy binaries, even if the updates are applied.

All the snapshots are visible to the administrator, so it's possible to
verify if there are suspicious snapshots.

Another more practical problem is that any user can pin the space used
by eg. root and cause ENOSPC.

Original report:
https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/484786

Signed-off-by: David Sterba 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason 
Signed-off-by: Greg Kroah-Hartman

btrfs: call mnt_drop_write after interrupted subvol deletion

2013-12-20T15:49:03+00:00

commit e43f998e47bae27e37e159915625e8d4b130153b upstream.

If btrfs_ioctl_snap_destroy blocks on the mutex and the process is
killed, mnt_write count is unbalanced and leads to unmountable
filesystem.

Signed-off-by: David Sterba 
Signed-off-by: Chris Mason 
Signed-off-by: Greg Kroah-Hartman

btrfs: change extent-same to copy entire argument struct

2013-09-21T15:05:31+00:00

btrfs_ioctl_file_extent_same() uses __put_user_unaligned() to copy some data
back to it's argument struct. Unfortunately, not all architectures provide
__put_user_unaligned(), so compiles break on them if btrfs is selected.

Instead, just copy the whole struct in / out at the start and end of
operations, respectively.

Signed-off-by: Mark Fasheh 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

Btrfs: btrfs_ioctl_default_subvol: Revert back to toplevel subvolume when arg is 0

2013-09-21T15:05:29+00:00

This patch makes it possible to set BTRFS_FS_TREE_OBJECTID as the default
subvolume by passing a subvolume id of 0.

Signed-off-by: chandan 
Reviewed-by: David Sterba 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

Btrfs: kill delay_iput arg to the wait_ordered functions

2013-09-21T15:05:27+00:00

This is a left over of how we used to wait for ordered extents, which was to
grab the inode and then run filemap flush on it.  However if we have an ordered
extent then we already are holding a ref on the inode, and we just use
btrfs_start_ordered_extent anyway, so there is no reason to have an extra ref on
the inode to start work on the ordered extent.  Thanks,

Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

btrfs: return btrfs error code for dev excl ops err

2013-09-01T12:16:35+00:00

now threads can return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS
as defined in btrfs.h for the dev excl operation error in
the FS, which means with this kernel would stop logging
(almost an user error) into the /var/log/messages

v2: accepts Josef' comment

Signed-off-by: Anand Jain 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

Btrfs: fix race conditions in BTRFS_IOC_FS_INFO ioctl

2013-09-01T12:16:25+00:00

The handler for the ioctl BTRFS_IOC_FS_INFO was reading the
number of devices before acquiring the device list mutex.

This could lead to inconsistent results because the update of
the device list and the number of devices counter (amongst other
counters related to the device list) are updated in volumes.c
while holding the device list mutex - except for 2 places, one
was volumes.c:btrfs_prepare_sprout() and the other was
volumes.c:device_list_add().

For example, if we have 2 devices, with IDs 1 and 2 and then add
a new device, with ID 3, and while adding the device is in progress
an BTRFS_IOC_FS_INFO ioctl arrives, it could return a number of
devices of 2 and a max dev id of 3. This would be incorrect.

Also, this ioctl handler was reading the fsid while it can be
updated concurrently. This can happen when while a new device is
being added and the current filesystem is in seeding mode.
Example:

$ mkfs.btrfs -f /dev/sdb1
$ mkfs.btrfs -f /dev/sdb2
$ btrfstune -S 1 /dev/sdb1
$ mount /dev/sdb1 /mnt/test
$ btrfs device add /dev/sdb2 /mnt/test

If during the last step a BTRFS_IOC_FS_INFO ioctl was requested, it
could read an fsid that was never valid (some bits part of the old
fsid and others part of the new fsid). Also, it could read a number
of devices that doesn't match the number of devices in the list and
the max device id, as explained before.

Signed-off-by: Filipe David Borba Manana 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

Btrfs: Make btrfs_header_chunk_tree_uuid() return unsigned long

2013-09-01T12:16:16+00:00

Internally, btrfs_header_chunk_tree_uuid() calculates an unsigned long, but
casts it to a pointer, while all callers cast it to unsigned long again.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

Btrfs: Make btrfs_header_fsid() return unsigned long

2013-09-01T12:16:15+00:00

Internally, btrfs_header_fsid() calculates an unsigned long, but casts
it to a pointer, while all callers cast it to unsigned long again.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

Btrfs: Remove superfluous casts from u64 to unsigned long long

2013-09-01T12:16:08+00:00

u64 is "unsigned long long" on all architectures now, so there's no need to
cast it when formatting it using the "ll" length modifier.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason