Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757983AbZGFJKl (ORCPT ); Mon, 6 Jul 2009 05:10:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753748AbZGFJKd (ORCPT ); Mon, 6 Jul 2009 05:10:33 -0400 Received: from mx2.redhat.com ([66.187.237.31]:53322 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752709AbZGFJKc (ORCPT ); Mon, 6 Jul 2009 05:10:32 -0400 Message-ID: <4A51BFEE.9050200@redhat.com> Date: Mon, 06 Jul 2009 17:12:14 +0800 From: Amerigo Wang User-Agent: Thunderbird 2.0.0.21 (X11/20090319) MIME-Version: 1.0 To: Tao Ma CC: linux-kernel@vger.kernel.org, Jeff Mahoney , Yan Zheng , Josef Bacik , Arjan , Chris Mason , akpm@linux-foundation.org, linux-btrfs@vger.kernel.org, Sven Wegener Subject: Re: [Patch v2] btrfs: use file_remove_suid() after i_mutex is held References: <20090706072043.6555.13669.sendpatchset@localhost.localdomain> <4A51AAFB.1000601@oracle.com> In-Reply-To: <4A51AAFB.1000601@oracle.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1561 Lines: 45 Tao Ma wrote: > Hi Amerigo, > > Amerigo Wang wrote: >> V1 -> V2: >> Move kmalloc() before mutex_lock(), suggested by Arjan. >> >> file_remove_suid() should be called with i_mutex held, >> file_update_time() too. So move them after mutex_lock(). >> >> Plus, check the return value of kmalloc(). >> >> Signed-off-by: WANG Cong >> Cc: Arjan >> Cc: Chris Mason >> Cc: Yan Zheng >> Cc: Sven Wegener >> Cc: Josef Bacik >> Cc: Jeff Mahoney >> >> --- >> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c >> index 7c3cd24..09ef5d6 100644 >> --- a/fs/btrfs/file.c >> +++ b/fs/btrfs/file.c >> @@ -944,14 +944,17 @@ static ssize_t btrfs_file_write(struct file >> *file, const char __user *buf, >> if (count == 0) >> goto out_nolock; >> >> + pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); >> + if (!pages) >> + goto out_nolock; > I guess you need to set err to -ENOMEM here so that the caller knows > what's wrong. With your patch, this function just return 0(since > num_written and err are both 0) with no error, and I guess it is worse > than kernel BUG out when the NULL pages is used later. Agree. Thanks, I will update it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/