From: Jiri Pirko <jiri@resnulli.us>
To: Jakub Kicinski <kuba@kernel.org>
Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com,
pabeni@redhat.com, jacob.e.keller@intel.com,
syzbot+d94d214ea473e218fc89@syzkaller.appspotmail.com
Subject: Re: [PATCH net-next] devlink: keep the instance mutex alive until references are gone
Date: Wed, 11 Jan 2023 10:16:55 +0100 [thread overview]
Message-ID: <Y75+hwMTgQaFp9qL@nanopsycho> (raw)
In-Reply-To: <20230111042908.988199-1-kuba@kernel.org>
Wed, Jan 11, 2023 at 05:29:08AM CET, kuba@kernel.org wrote:
>The reference needs to keep the instance memory around, but also
>the instance lock must remain valid. Users will take the lock,
>check registration status and release the lock. mutex_destroy()
>etc. belong in the same place as the freeing of the memory.
>
>Unfortunately lockdep_unregister_key() sleeps so we need
>to switch the an rcu_work.
>
>Note that the problem is a bit hard to repro, because
>devlink_pernet_pre_exit() iterates over registered instances.
>AFAIU the instances must get devlink_free()d concurrently with
>the namespace getting deleted for the problem to occur.
>
>Reported-by: syzbot+d94d214ea473e218fc89@syzkaller.appspotmail.com
>Fixes: 9053637e0da7 ("devlink: remove the registration guarantee of references")
>Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
>---
>Jiri, this will likely conflict with your series, sorry :(
Yeah, I will rebase and send v5 after this is applied, no worries.
next prev parent reply other threads:[~2023-01-11 9:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-11 4:29 [PATCH net-next] devlink: keep the instance mutex alive until references are gone Jakub Kicinski
2023-01-11 9:16 ` Jiri Pirko [this message]
2023-01-11 9:26 ` Jiri Pirko
2023-01-11 21:20 ` Jacob Keller
2023-01-12 5:00 ` patchwork-bot+netdevbpf
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