Re: [PATCH] mm: Fix a null ptr deref with CONFIG_DEBUG_VM enabled in wp_page_reuse

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Jul 27, 2022 at 03:14:07PM -0400, Zack Rusin wrote:
> From: Zack Rusin <zackr@xxxxxxxxxx>
> 
> Write page faults on last references might not have a valid page anymore.
> wp_page_reuse has always dealt with that scenario by making
> sure the page isn't null (or the reference was shared) before doing
> anything with it. Recently added checks in VM_BUG_ON (enabled by the
> CONFIG_DEBUG_VM option) use PageAnon helpers which assume the passed
> page is never null, before making sure there is a valid page to work
> with.
> 
> Move the VM_BUG_ON, which unconditionally uses the page, after the
> code that checks that we have a valid one.

Message-ID: <CAHk-=wh_TrgNm6vz7=7CgZppr0UrZ9TwLyb3dgPXyG-w=a8kJQ@xxxxxxxxxxxxxx>





[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux