From adcd459ff805ce5e11956cfa1e9aa85471b6ae8d Mon Sep 17 00:00:00 2001 From: Andrea Righi Date: Sun, 21 May 2023 10:28:13 +0200 Subject: [PATCH] ovl: validate superblock in OVL_FS() When CONFIG_OVERLAY_FS_DEBUG is enabled add an explicit check to make sure that OVL_FS() is always used with a valid overlayfs superblock. Otherwise trigger a WARN_ON_ONCE(). Reviewed-by: Amir Goldstein Signed-off-by: Andrea Righi Signed-off-by: Amir Goldstein --- fs/overlayfs/ovl_entry.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index edb457544b5f..e9539f98e86a 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -121,6 +121,9 @@ extern struct file_system_type ovl_fs_type; static inline struct ovl_fs *OVL_FS(struct super_block *sb) { + if (IS_ENABLED(CONFIG_OVERLAY_FS_DEBUG)) + WARN_ON_ONCE(sb->s_type != &ovl_fs_type); + return (struct ovl_fs *)sb->s_fs_info; }