On Fri, Jan 8, 2016 at 6:09 PM, Rui Wang <rui.y.wang@xxxxxxxxx> wrote: > ovl_remove_upper() should do d_drop() only after it successfully > removes the dir, otherwise a subsequent getcwd() system call will > fail, breaking userspace programs. > > This is to fix: https://bugzilla.kernel.org/show_bug.cgi?id=110491 > > Signed-off-by: Rui Wang <rui.y.wang@xxxxxxxxx> Reviewed-by: Konstantin Khlebnikov <koct9i@xxxxxxxxx> The same problem also in ovl_remove_and_whiteout() - when we remove non-pure dentry. It checks that directory isn't empty before, but I'm sure that vfs_rename which exchanges dentry and whiteout could fail for some reason and we'll end with unhashed dentry when nothing actually has been changed. > --- > fs/overlayfs/dir.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c > index 692ceda..36d6a5b 100644 > --- a/fs/overlayfs/dir.c > +++ b/fs/overlayfs/dir.c > @@ -618,7 +618,8 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) > * sole user of this dentry. Too tricky... Just unhash for > * now. > */ > - d_drop(dentry); > + if (!err) > + d_drop(dentry); > mutex_unlock(&dir->i_mutex); > > return err; > -- > 1.7.5.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
