diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-07-04 16:49:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-10 11:49:28 +0200 |
| commit | b82c78948a5311ca3952900dffbee5c932c2d03b (patch) | |
| tree | 61852b0044924d2dbfa9159a19ba6ca33563ef54 /fs/overlayfs | |
| parent | 34bf12312bd4222a1b945be3f58173edc8aa3f22 (diff) | |
ovl: handle ATTR_KILL*
commit b99c2d913810e56682a538c9f2394d76fca808f8 upstream.
Before 4bacc9c9234c ("overlayfs: Make f_path...") file->f_path pointed to
the underlying file, hence suid/sgid removal on write worked fine.
After that patch file->f_path pointed to the overlay file, and the file
mode bits weren't copied to overlay_inode->i_mode. So the suid/sgid
removal simply stopped working.
The fix is to copy the mode bits, but then ovl_setattr() needs to clear
ATTR_MODE to avoid the BUG() in notify_change(). So do this first, then in
the next patch copy the mode.
Reported-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: Eric Schultz <eric@startuperic.com>
Cc: Eric Hameleers <alien@slackware.com>
[backported by Eric Hameleers as seen in https://bugzilla.kernel.org/show_bug.cgi?id=150711]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/inode.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 0597820f5d9d..4f729ffff75d 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -63,6 +63,9 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr) if (!err) { upperdentry = ovl_dentry_upper(dentry); + if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) + attr->ia_valid &= ~ATTR_MODE; + mutex_lock(&upperdentry->d_inode->i_mutex); err = notify_change(upperdentry, attr, NULL); if (!err) |