From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [PATCH] ext4: fix NULL pointer dereference in ext4_quota_off Date: Mon, 16 May 2011 12:13:29 +0200 Message-ID: <20110516101329.GC5344@quack.suse.cz> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Amir Goldstein , Ext4 Developers List , Theodore Tso , Jan Kara To: Lukas Czerner Return-path: Received: from cantor2.suse.de ([195.135.220.15]:53921 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753229Ab1EPKNv (ORCPT ); Mon, 16 May 2011 06:13:51 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon 16-05-11 11:49:22, Lukas Czerner wrote: > On Mon, 16 May 2011, Amir Goldstein wrote: > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > > index fc827bb..2689351 100644 > > --- a/fs/ext4/super.c > > +++ b/fs/ext4/super.c > > @@ -4681,6 +4681,9 @@ static int ext4_quota_off(struct super_block > > *sb, int type) > > if (test_opt(sb, DELALLOC)) > > sync_filesystem(sb); > > > > + if (!inode) > > + goto out; > > Just out of curiosity, why would the quota inode be NULL ? Because quota is already turned off (we then release all references to quota file). Just what I don't understand is why in Amir's testing quota is not turned on before calling quota off. Because when I run the same test, I don't trigger the issue. Honza -- Jan Kara SUSE Labs, CR