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Date: Fri, 6 Nov 2026 19:11:50 +0800
From: Herbert Xu <herbert@gondor.apana.org.au>
To: Thorsten Blum <blum@kernel.org>
Cc: Laurent Vivier <lvivier@redhat.com>,
	Olivia Mackall <olivia@selenic.com>,
	Rusty Russell <rusty@rustcorp.com.au>, Amos Kong <akong@redhat.com>,
	virtualization@lists.linux.dev, linux-crypto@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] hwrng: virtio - prevent use-after-free after a failed
 restore
Message-ID: <au219vQfcYE0maYw@gondor.apana.org.au>
References: <20261016103640.4989-2-blum@kernel.org>
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In-Reply-To: <20261016103640.4989-2-blum@kernel.org>

On Fri, Oct 16, 2026 at 12:36:40PM +0200, Thorsten Blum wrote:
> remove_common() frees the driver data during freeze, but does not clear
> vdev->priv, which points to freed memory. If probe_common() then fails
> during restore, a later remove or freeze can dereference the dangling
> pointer.
> 
> Clear vdev->priv on the probe_common() error cleanup path and before
> freeing the driver data in remove_common(). Also reset the device and
> return early from remove_common() if vdev->priv is already NULL for a
> safe teardown after a failed restore.
> 
> Fixes: 08e53fbdb85c ("virtio-rng: support multiple virtio-rng devices")
> Cc: stable@vger.kernel.org
> Signed-off-by: Thorsten Blum <blum@kernel.org>
> ---
>  drivers/char/hw_random/virtio-rng.c | 7 +++++++
>  1 file changed, 7 insertions(+)

Please respond to this comment:

https://sashiko.dev/#/patchset/20261016103640.4989-2-blum%40kernel.org

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt