From: Sabrina Dubroca <sd@queasysnail.net>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jakub Kicinski <kuba@kernel.org>,
netdev@vger.kernel.org, Dave Watson <davejwatson@fb.com>,
Vakul Garg <vakul.garg@nxp.com>,
Boris Pismenny <borisp@nvidia.com>,
John Fastabend <john.fastabend@gmail.com>
Subject: Re: [PATCH net 5/5] tls: don't decrypt the next record if it's of a different type
Date: Fri, 8 Sep 2023 17:38:49 +0200 [thread overview]
Message-ID: <ZPtACbUa9rQz0uFq@hog> (raw)
In-Reply-To: <ZPq51KxgmELpTgOs@gondor.apana.org.au>
2023-09-08, 14:06:12 +0800, Herbert Xu wrote:
> On Thu, Sep 07, 2023 at 02:21:59PM +0200, Sabrina Dubroca wrote:
> >
> > Herbert, WDYT? We're calling tls_do_decryption twice from the same
> > tls_sw_recvmsg invocation, first with darg->async = true, then with
> > darg->async = false. Is it ok to use ctx->async_wait for both, or do
> > we need a fresh one as in this patch?
>
> Yes I think your patch makes sense and the existing code could
> malfunction if two decryption requests occur during the same
> tls_sw_recvmsg call, with the first being async and the second
> being sync.
Thanks for confirming. I'll add it to v2 of this series.
> However, I'm still unsure about the case where two async decryption
> requests occur during the same tls_sw_recvmsg call. Or perhaps this
> is not possible due to other constraints that are not obvious?
tls_decrypt_done only runs the completion when decrypt_pending drops
to 0, so this should be covered.
I wonder if this situation could happen:
tls_sw_recvmsg
process first record
decrypt_pending = 1
CB runs
decrypt_pending = 0
complete(&ctx->async_wait.completion);
process second record
decrypt_pending = 1
tls_sw_recvmsg reaches "recv_end"
decrypt_pending != 0
crypto_wait_req sees the first completion of ctx->async_wait and proceeds
CB runs
decrypt_pending = 0
complete(&ctx->async_wait.completion);
With my force_async patch I've managed to run into situations where
the CB runs before we reach the crypto_wait_req at the end of
tls_sw_recvmsg (patch 4 of this series [1]). I don't know if it's a
side-effect of my hack or if it's realistic.
[1] https://patchwork.kernel.org/project/netdevbpf/patch/e094325019f7fd960470c10efda41c1b7f9bc54f.1694018970.git.sd@queasysnail.net/
--
Sabrina
next prev parent reply other threads:[~2023-09-08 15:39 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-06 17:08 [PATCH net 0/5] tls: fix some issues with async encryption Sabrina Dubroca
2023-09-06 17:08 ` [PATCH net 1/5] net: tls: handle -EBUSY on async encrypt/decrypt requests Sabrina Dubroca
2023-09-07 1:50 ` Jakub Kicinski
2023-09-07 15:11 ` Simon Horman
2023-09-08 6:10 ` Herbert Xu
2023-09-08 15:55 ` Sabrina Dubroca
2023-09-08 21:26 ` Jakub Kicinski
2023-09-09 0:53 ` Herbert Xu
2023-09-12 4:43 ` Herbert Xu
2023-09-12 15:37 ` Sabrina Dubroca
2023-09-14 9:00 ` Herbert Xu
2023-09-06 17:08 ` [PATCH net 2/5] tls: fix use-after-free with partial reads and async decrypt Sabrina Dubroca
2023-09-07 2:05 ` Jakub Kicinski
2023-09-07 13:56 ` Sabrina Dubroca
2023-09-06 17:08 ` [PATCH net 3/5] tls: fix returned read length with async !zc decrypt Sabrina Dubroca
2023-09-06 17:08 ` [PATCH net 4/5] tls: fix race condition in async decryption of corrupted records Sabrina Dubroca
2023-09-06 17:08 ` [PATCH net 5/5] tls: don't decrypt the next record if it's of a different type Sabrina Dubroca
2023-09-07 3:47 ` Jakub Kicinski
2023-09-07 12:21 ` Sabrina Dubroca
2023-09-07 17:08 ` Jakub Kicinski
2023-09-08 6:06 ` Herbert Xu
2023-09-08 15:38 ` Sabrina Dubroca [this message]
2023-09-12 4:38 ` Herbert Xu
2023-09-13 13:25 ` Sabrina Dubroca
2023-09-14 9:45 ` Herbert Xu
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=ZPtACbUa9rQz0uFq@hog \
--to=sd@queasysnail.net \
--cc=borisp@nvidia.com \
--cc=davejwatson@fb.com \
--cc=herbert@gondor.apana.org.au \
--cc=john.fastabend@gmail.com \
--cc=kuba@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=vakul.garg@nxp.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 NNTP newsgroup(s).