From: Jakub Kicinski <kuba@kernel.org>
To: Saurabh Sengar <ssengar@linux.microsoft.com>
Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
decui@microsoft.com, andrew+netdev@lunn.ch, davem@davemloft.net,
edumazet@google.com, pabeni@redhat.com, horms@kernel.org,
ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org,
john.fastabend@gmail.com, sdf@fomichev.me, kuniyu@amazon.com,
ahmed.zaki@intel.com, aleksander.lobakin@intel.com,
linux-hyperv@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
ssengar@microsoft.com, stable@vger.kernel.org
Subject: Re: [PATCH net,v2] hv_netvsc: fix potential deadlock in netvsc_vf_setxdp()
Date: Thu, 22 May 2025 15:13:46 -0700 [thread overview]
Message-ID: <20250522151346.57390f40@kernel.org> (raw)
In-Reply-To: <1747823103-3420-1-git-send-email-ssengar@linux.microsoft.com>
On Wed, 21 May 2025 03:25:03 -0700 Saurabh Sengar wrote:
> The MANA driver's probe registers netdevice via the following call chain:
>
> mana_probe()
> register_netdev()
> register_netdevice()
>
> register_netdevice() calls notifier callback for netvsc driver,
> holding the netdev mutex via netdev_lock_ops().
>
> Further this netvsc notifier callback end up attempting to acquire the
> same lock again in dev_xdp_propagate() leading to deadlock.
>
> netvsc_netdev_event()
> netvsc_vf_setxdp()
> dev_xdp_propagate()
>
> This deadlock was not observed so far because net_shaper_ops was never set,
The lock is on the VF, I think you meant to say that no device you use
in Azure is ops locked?
There's also the call to netvsc_register_vf() on probe path, please
fix or explain why it doesn't need locking in the commit message.
--
pw-bot: cr
next prev parent reply other threads:[~2025-05-22 22:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-21 10:25 [PATCH net,v2] hv_netvsc: fix potential deadlock in netvsc_vf_setxdp() Saurabh Sengar
2025-05-21 10:51 ` Subbaraya Sundeep
2025-05-22 22:13 ` Jakub Kicinski [this message]
2025-05-23 4:06 ` Saurabh Singh Sengar
2025-05-23 12:48 ` Saurabh Singh Sengar
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=20250522151346.57390f40@kernel.org \
--to=kuba@kernel.org \
--cc=ahmed.zaki@intel.com \
--cc=aleksander.lobakin@intel.com \
--cc=andrew+netdev@lunn.ch \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=decui@microsoft.com \
--cc=edumazet@google.com \
--cc=haiyangz@microsoft.com \
--cc=hawk@kernel.org \
--cc=horms@kernel.org \
--cc=john.fastabend@gmail.com \
--cc=kuniyu@amazon.com \
--cc=kys@microsoft.com \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sdf@fomichev.me \
--cc=ssengar@linux.microsoft.com \
--cc=ssengar@microsoft.com \
--cc=stable@vger.kernel.org \
--cc=wei.liu@kernel.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).