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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.