patches/kernel/0002-UBUNTU-SAUCE-overlayfs-fix-shitfs-special-casing.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Christian Brauner <christian.brauner@ubuntu.com>
   3 Date: Wed, 6 May 2020 10:55:28 +0200
   4 Subject: [PATCH] UBUNTU: SAUCE: overlayfs: fix shitfs special-casing
   5
   6 BugLink: https://bugs.launchpad.net/bugs/1876645
   7
   8 When I picked up Andrei's patch I ported it wrong. We need to initialize
   9 realpath before dereferencing it obviously.
  10
  11 Cc: Stefan Bader <stefan.bader@canonical.com>
  12 Cc: Seth Forshee <seth.forshee@canonical.com>
  13 Cc: Kamal Mostafa <kamal@canonical.com>
  14 Cc: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  15 Cc: Andrei Vagin <avagin@gmail.com>
  16 Fixes: 4e1f6efeedae ("UBUNTU: SAUCE: overlayfs: use shiftfs hacks only with shiftfs as underlay")
  17 Link: https://bugs.launchpad.net/bugs/1857257
  18 Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
  19 Acked-by: Stefan Bader <stefan.bader@canonical.com>
  20 Acked-by: Kleber Souza <kleber.souza@canonical.com>
  21 Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
  22 ---
  23  fs/overlayfs/file.c | 1 +
  24  1 file changed, 1 insertion(+)
  25
  26 diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
  27 index a2faa086ee4b..a406736588d4 100644
  28 --- a/fs/overlayfs/file.c
  29 +++ b/fs/overlayfs/file.c
  30 @@ -32,6 +32,7 @@ static struct file *ovl_open_realfile(const struct file *file,
  31         int flags = file->f_flags | O_NOATIME | FMODE_NONOTIFY;
  32
  33         old_cred = ovl_override_creds(inode->i_sb);
  34 +       ovl_path_real(file->f_path.dentry, &realpath);
  35         if (realpath.dentry->d_sb->s_magic == SHIFTFS_MAGIC)
  36                 realfile = open_with_fake_path(&realpath, flags, realinode,
  37                                                current_cred());