3.8.13.18 -stable review patch. If anyone has any objections, please let me know.
------------------ From: David Sterba <[email protected]> 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 <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: Chris Mason <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- fs/btrfs/ioctl.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 47d5dcd..1ce5240 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1494,6 +1494,12 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file, printk(KERN_INFO "btrfs: Snapshot src from " "another FS\n"); ret = -EINVAL; + } else if (!inode_owner_or_capable(src_inode)) { + /* + * Subvolume creation is not restricted, but snapshots + * are limited to own subvolumes only + */ + ret = -EPERM; } else { ret = btrfs_mksubvol(&file->f_path, name, namelen, BTRFS_I(src_inode)->root, -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
