From: Jakub Kicinski <kuba@kernel.org>
To: Juntong Deng <juntong.deng@outlook.com>
Cc: syzbot+29c22ea2d6b2c5fd2eae@syzkaller.appspotmail.com,
Sabrina Dubroca <sd@queasysnail.net>,
borisp@nvidia.com, netdev@vger.kernel.org,
john.fastabend@gmail.com, linux-kernel@vger.kernel.org,
edumazet@google.com, pabeni@redhat.com,
linux-kernel-mentees@lists.linuxfoundation.org,
davem@davemloft.net
Subject: Re: [PATCH v2] net/tls: Fix slab-use-after-free in tls_encrypt_done
Date: Wed, 18 Oct 2023 18:25:55 -0700 [thread overview]
Message-ID: <20231018182555.28f1a774@kernel.org> (raw)
In-Reply-To: <VI1P193MB0752321F24623E024C87886A99D6A@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM>
On Wed, 18 Oct 2023 00:22:15 +0800 Juntong Deng wrote:
> In the current implementation, ctx->async_wait.completion is completed
> after spin_lock_bh, which causes tls_sw_release_resources_tx to
> continue executing and return to tls_sk_proto_cleanup, then return
> to tls_sk_proto_close, and after that enter tls_sw_free_ctx_tx to kfree
> the entire struct tls_sw_context_tx (including ctx->encrypt_compl_lock).
>
> Since ctx->encrypt_compl_lock has been freed, subsequent spin_unlock_bh
> will result in slab-use-after-free error. Due to SMP, even using
> spin_lock_bh does not prevent tls_sw_release_resources_tx from continuing
> on other CPUs. After tls_sw_release_resources_tx is woken up, there is no
> attempt to hold ctx->encrypt_compl_lock again, therefore everything
> described above is possible.
Whoever triggered the Tx should wait for all outstanding encryption
to finish before exiting sendmsg() (or alike). This looks like
a band-aid. Sabrina is working on fixes for the async code, lets
get those in first before attempting spot fixes.
--
pw-bot: cr
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
prev parent reply other threads:[~2023-10-19 1:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-17 16:22 [PATCH v2] net/tls: Fix slab-use-after-free in tls_encrypt_done Juntong Deng
2023-10-19 1:25 ` Jakub Kicinski [this message]
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=20231018182555.28f1a774@kernel.org \
--to=kuba@kernel.org \
--cc=borisp@nvidia.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=john.fastabend@gmail.com \
--cc=juntong.deng@outlook.com \
--cc=linux-kernel-mentees@lists.linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sd@queasysnail.net \
--cc=syzbot+29c22ea2d6b2c5fd2eae@syzkaller.appspotmail.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).