kernel: backport upstream overlayfs fixes

[openwrt/staging/lynxis/omap.git] / target / linux / generic / patches-4.4 / 051-0004-ovl-remove-posix_acl_default-from-workdir.patch

diff --git a/target/linux/generic/patches-4.4/051-0004-ovl-remove-posix_acl_default-from-workdir.patch b/target/linux/generic/patches-4.4/051-0004-ovl-remove-posix_acl_default-from-workdir.patch
new file mode 100644 (file)
index 0000000..1785c9a
--- /dev/null
+++ b/target/linux/generic/patches-4.4/051-0004-ovl-remove-posix_acl_default-from-workdir.patch
@@ -0,0 +1,49 @@
+From c11b9fdd6a612f376a5e886505f1c54c16d8c380 Mon Sep 17 00:00:00 2001
+From: Miklos Szeredi <mszeredi@redhat.com>
+Date: Thu, 1 Sep 2016 11:11:59 +0200
+Subject: [PATCH] ovl: remove posix_acl_default from workdir
+
+Clear out posix acl xattrs on workdir and also reset the mode after
+creation so that an inherited sgid bit is cleared.
+
+Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
+Cc: <stable@vger.kernel.org>
+---
+ fs/overlayfs/super.c | 19 +++++++++++++++++++
+ 1 file changed, 19 insertions(+)
+
+--- a/fs/overlayfs/super.c
++++ b/fs/overlayfs/super.c
+@@ -773,6 +773,10 @@ retry:
+               struct kstat stat = {
+                       .mode = S_IFDIR | 0,
+               };
++              struct iattr attr = {
++                      .ia_valid = ATTR_MODE,
++                      .ia_mode = stat.mode,
++              };
+ 
+               if (work->d_inode) {
+                       err = -EEXIST;
+@@ -788,6 +792,21 @@ retry:
+               err = ovl_create_real(dir, work, &stat, NULL, NULL, true);
+               if (err)
+                       goto out_dput;
++
++              err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);
++              if (err && err != -ENODATA)
++                      goto out_dput;
++
++              err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS);
++              if (err && err != -ENODATA)
++                      goto out_dput;
++
++              /* Clear any inherited mode bits */
++              mutex_lock(&work->d_inode->i_mutex);
++              err = notify_change(work, &attr, NULL);
++              mutex_unlock(&work->d_inode->i_mutex);
++              if (err)
++                      goto out_dput;
+       }
+ out_unlock:
+       mutex_unlock(&dir->i_mutex);