diff options
| author | Miklos Szeredi <miklos@szeredi.hu> | 2015-12-04 19:18:48 +0100 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-04-13 17:14:29 -0400 |
| commit | 2cadb57dff500076a87b934cac64bb5a2293b644 (patch) | |
| tree | 80c1f7fccfb9d746124a842065fc358baff0e3d0 /fs | |
| parent | 50d93d381508139a35a0f91a364fbdc1a38885d4 (diff) | |
ovl: fix permission checking for setattr
[ Upstream commit acff81ec2c79492b180fade3c2894425cd35a545 ]
[Al Viro] The bug is in being too enthusiastic about optimizing ->setattr()
away - instead of "copy verbatim with metadata" + "chmod/chown/utimes"
(with the former being always safe and the latter failing in case of
insufficient permissions) it tries to combine these two. Note that copyup
itself will have to do ->setattr() anyway; _that_ is where the elevated
capabilities are right. Having these two ->setattr() (one to set verbatim
copy of metadata, another to do what overlayfs ->setattr() had been asked
to do in the first place) combined is where it breaks.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/overlayfs/inode.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index e505b44a9184..edd2a4a5fd3c 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -62,15 +62,15 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr) if (err) goto out; - upperdentry = ovl_dentry_upper(dentry); - if (upperdentry) { + err = ovl_copy_up(dentry); + if (!err) { + upperdentry = ovl_dentry_upper(dentry); + mutex_lock(&upperdentry->d_inode->i_mutex); err = notify_change(upperdentry, attr, NULL); if (!err) ovl_copyattr(upperdentry->d_inode, dentry->d_inode); mutex_unlock(&upperdentry->d_inode->i_mutex); - } else { - err = ovl_copy_up_last(dentry, attr, false); } ovl_drop_write(dentry); out: |