diff options
authorMiklos Szeredi <mszeredi@redhat.com>2016-07-04 16:49:48 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-08-10 11:49:28 +0200
commitb82c78948a5311ca3952900dffbee5c932c2d03b (patch)
parent34bf12312bd4222a1b945be3f58173edc8aa3f22 (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>
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;
err = notify_change(upperdentry, attr, NULL);
if (!err)