From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx185.postini.com [74.125.245.185]) by kanga.kvack.org (Postfix) with SMTP id D9B2B6B0083 for ; Tue, 22 May 2012 16:45:59 -0400 (EDT) Date: Tue, 22 May 2012 13:45:58 -0700 From: Andrew Morton Subject: Re: [PATCH] hugetlb: fix resv_map leak in error path Message-Id: <20120522134558.49255899.akpm@linux-foundation.org> In-Reply-To: <20120521202814.E01F0FE1@kernel> References: <20120521202814.E01F0FE1@kernel> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: cl@linux.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, aarcange@redhat.com, kosaki.motohiro@jp.fujitsu.com, hughd@google.com, rientjes@google.com, adobriyan@gmail.com, mel@csn.ul.ie On Mon, 21 May 2012 13:28:14 -0700 Dave Hansen wrote: > When called for anonymous (non-shared) mappings, > hugetlb_reserve_pages() does a resv_map_alloc(). It depends on > code in hugetlbfs's vm_ops->close() to release that allocation. > > However, in the mmap() failure path, we do a plain unmap_region() > without the remove_vma() which actually calls vm_ops->close(). > > This is a decent fix. This leak could get reintroduced if > new code (say, after hugetlb_reserve_pages() in > hugetlbfs_file_mmap()) decides to return an error. But, I think > it would have to unroll the reservation anyway. How far back does this bug go? The patch applies to 3.4 but gets rejects in 3.3 and earlier. > This hasn't been extensively tested. Pretty much compile and > boot tested along with Christoph's test case: > > http://marc.info/?l=linux-mm&m=133728900729735 That isn't my favoritest ever changelog text :( -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org