| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 68/68] vfs: fix deadlock in file_remove_privs() on overlayfs | Date | Mon, 8 Aug 2016 21:11:43 +0200 |
| |
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Miklos Szeredi <mszeredi@redhat.com>
commit c1892c37769cf89c7e7ba57528ae2ccb5d153c9b upstream.
file_remove_privs() is called with inode lock on file_inode(), which proceeds to calling notify_change() on file->f_path.dentry. Which triggers the WARN_ON_ONCE(!inode_is_locked(inode)) in addition to deadlocking later when ovl_setattr tries to lock the underlying inode again.
Fix this mess by not mixing the layers, but doing everything on underlying dentry/inode.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 07a2daab49c5 ("ovl: Copy up underlying inode's ->i_mode to overlay inode") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/inode.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/fs/inode.c +++ b/fs/inode.c @@ -1733,8 +1733,8 @@ static int __remove_privs(struct dentry */ int file_remove_privs(struct file *file) { - struct dentry *dentry = file->f_path.dentry; - struct inode *inode = d_inode(dentry); + struct dentry *dentry = file_dentry(file); + struct inode *inode = file_inode(file); int kill; int error = 0; @@ -1742,7 +1742,7 @@ int file_remove_privs(struct file *file) if (IS_NOSEC(inode)) return 0; - kill = file_needs_remove_privs(file); + kill = dentry_needs_remove_privs(dentry); if (kill < 0) return kill; if (kill)
|