lkml.org 
[lkml]   [2021]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v1] hugetlb, userfaultfd: Fix reservation restore on userfaultfd error
On Tue, 16 Nov 2021 15:57:32 -0800 Mina Almasry <almasrymina@google.com> wrote:

> Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we
> bail out using "goto out_release_unlock;" in the cases where idx >=
> size, or !huge_pte_none(), the code will detect that new_pagecache_page
> == false, and so call restore_reserve_on_error().
> In this case I see restore_reserve_on_error() delete the reservation,
> and the following call to remove_inode_hugepages() will increment
> h->resv_hugepages causing a 100% reproducible leak.
>
> We should treat the is_continue case similar to adding a page into the
> pagecache and set new_pagecache_page to true, to indicate that there is
> no reservation to restore on the error path, and we need not call
> restore_reserve_on_error().
>
> Cc: Wei Xu <weixugc@google.com>
>
> Fixes: c7b1850dfb41 ("hugetlb: don't pass page cache pages to restore_reserve_on_error")

I added cc:stable to this.

\
 
 \ /
  Last update: 2021-11-17 01:34    [W:2.030 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site