From: Uladzislau Rezki <urezki@gmail.com>
To: vjitta@codeaurora.org
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, vinmenon@codeaurora.org
Subject: Re: [PATCH] mm: vmalloc: Prevent use after free in _vm_unmap_aliases
Date: Thu, 18 Mar 2021 17:59:07 +0100 [thread overview]
Message-ID: <20210318165907.GA10448@pc638.lan> (raw)
In-Reply-To: <1616062105-23263-1-git-send-email-vjitta@codeaurora.org>
On Thu, Mar 18, 2021 at 03:38:25PM +0530, vjitta@codeaurora.org wrote:
> From: Vijayanand Jitta <vjitta@codeaurora.org>
>
> A potential use after free can occur in _vm_unmap_aliases
> where an already freed vmap_area could be accessed, Consider
> the following scenario:
>
> Process 1 Process 2
>
> __vm_unmap_aliases __vm_unmap_aliases
> purge_fragmented_blocks_allcpus rcu_read_lock()
> rcu_read_lock()
> list_del_rcu(&vb->free_list)
> list_for_each_entry_rcu(vb .. )
> __purge_vmap_area_lazy
> kmem_cache_free(va)
> va_start = vb->va->va_start
Or maybe we should switch to kfree_rcu() instead of kmem_cache_free()?
--
Vlad Rezki
next prev parent reply other threads:[~2021-03-18 16:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 10:08 [PATCH] mm: vmalloc: Prevent use after free in _vm_unmap_aliases vjitta
2021-03-18 16:59 ` Uladzislau Rezki [this message]
2021-03-24 3:29 ` Vijayanand Jitta
2021-03-24 13:32 ` Uladzislau Rezki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210318165907.GA10448@pc638.lan \
--to=urezki@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=vinmenon@codeaurora.org \
--cc=vjitta@codeaurora.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).