This is a note to let you know that I've just added the patch titled ovl: handle ATTR_KILL* to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ovl-handle-attr_kill.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b99c2d913810e56682a538c9f2394d76fca808f8 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi <mszeredi@xxxxxxxxxx> Date: Mon, 4 Jul 2016 16:49:48 +0200 Subject: ovl: handle ATTR_KILL* From: Miklos Szeredi <mszeredi@xxxxxxxxxx> 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@xxxxxxxxxx> Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx> Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Cc: Eric Schultz <eric@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/overlayfs/inode.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -63,6 +63,9 @@ int ovl_setattr(struct dentry *dentry, s 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) Patches currently in stable-queue which might be from mszeredi@xxxxxxxxxx are queue-4.4/ovl-handle-attr_kill.patch queue-4.4/9p-use-file_dentry.patch queue-4.4/locks-use-file_inode.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html