From: Jakub Kicinski <kuba@kernel.org>
To: Eric Dumazet <edumazet@google.com>, Ankit Garg <nktgrg@google.com>
Cc: Joshua Washington <joshwash@google.com>,
netdev@vger.kernel.org,
Harshitha Ramamurthy <hramamurthy@google.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Paolo Abeni <pabeni@redhat.com>,
Willem de Bruijn <willemb@google.com>,
Praveen Kaligineedi <pkaligineedi@google.com>,
Catherine Sullivan <csully@google.com>,
Luigi Rizzo <lrizzo@google.com>, Jon Olson <jonolson@google.com>,
Sagi Shahar <sagis@google.com>, Bailey Forrest <bcf@google.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH net 0/2] gve: fix crashes on invalid TX queue indices
Date: Fri, 30 Jan 2026 16:38:25 -0800 [thread overview]
Message-ID: <20260130163825.3b63222a@kernel.org> (raw)
In-Reply-To: <CANn89iJ=Gfjves4qN6hu_VRPSedVRosJsvEQC_irFnEJU_eMLg@mail.gmail.com>
On Fri, 30 Jan 2026 21:56:07 +0100 Eric Dumazet wrote:
> Jakub, the issue is that before 4.20, calling synchronize_rcu()
> instead of synchronize_rcu_bh()
> was probably a bug. I suspect we had more issues like that.
>
> __dev_queue_xmit takes a rcu_read_lock_bh(), while the code (that you
> added in 2018 [1])
> to update the queue netif_set_real_num_tx_queues does synchronize_net()
> (aka synchronize_rcu()) and in earlier times, it would mean that this
> would maybe return too soon (say on preemptible kernels)
>
> [...]
>
> So perhaps a fix for pre 4.20 kernel would be: (I kept the
> synchronize_net() to be really cautious and because I really do not
> want to test)
Sounds entirely plausible, FWIW. Ankit, this would mean that you have
to convince RHEL / Rocky to take Eric's patch. Oldest kernel we can
patch upstream is 5.10, AFAIK.
prev parent reply other threads:[~2026-01-31 0:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-05 23:25 [PATCH net 0/2] gve: fix crashes on invalid TX queue indices Joshua Washington
2026-01-05 23:25 ` [PATCH net 1/2] gve: drop packets on invalid queue indices in GQI TX path Joshua Washington
2026-01-05 23:25 ` [PATCH net 2/2] gve: drop packets on invalid queue indices in DQO " Joshua Washington
2026-01-07 2:22 ` [PATCH net 0/2] gve: fix crashes on invalid TX queue indices Jakub Kicinski
2026-01-08 15:35 ` Ankit Garg
2026-01-08 16:31 ` Jakub Kicinski
2026-01-08 16:37 ` Eric Dumazet
2026-01-08 20:53 ` Ankit Garg
2026-01-30 20:56 ` Eric Dumazet
2026-01-31 0:38 ` 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=20260130163825.3b63222a@kernel.org \
--to=kuba@kernel.org \
--cc=andrew+netdev@lunn.ch \
--cc=bcf@google.com \
--cc=csully@google.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=hramamurthy@google.com \
--cc=jonolson@google.com \
--cc=joshwash@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lrizzo@google.com \
--cc=netdev@vger.kernel.org \
--cc=nktgrg@google.com \
--cc=pabeni@redhat.com \
--cc=pkaligineedi@google.com \
--cc=sagis@google.com \
--cc=stable@vger.kernel.org \
--cc=willemb@google.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 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.