From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 801F13AEF4D for ; Wed, 8 Apr 2026 13:39:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775655564; cv=none; b=LlpR8G20vC8jTbhEVraHarzm7slu1eB+c+cjvqInpz+5oT3RJi0s7/QWjwnr3yPZJqKQiA8fU3IxO4aruPWgYCfncbb18nGm2MCO5FAGYqlRzf7cyw6eXvIwuXbr72CMxfuXHHHEAAFpmfH/qDmwmxF7ux1PFM0AxXLLD5dhsXY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775655564; c=relaxed/simple; bh=VUgmsahK51dNWv/faRJdU7qhNO1K1vnpUdnASSjVgfE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HLq/0+flw03XdsYIkQm2HipNw3x4KfX61nI1q15/Ccths6UKuTC2sgkudq3prYN5WGDKhAWM+a0rS/EV8A/vFsEbqhIhEHb+Zv/geLhh1dumJw71CRX+3WzIWsFazklBYkdF8/jzrj/sHGAf5GElVXBJQChwVVWvykW1ng8eZdU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sb4Ue7eg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sb4Ue7eg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D5B1C19421; Wed, 8 Apr 2026 13:39:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775655564; bh=VUgmsahK51dNWv/faRJdU7qhNO1K1vnpUdnASSjVgfE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sb4Ue7eguoJX3t2nV9WqyPM+aq4CfiWzrPJDnLqdZWFuqLYcbp+VKp+B16tfCBSr5 5GT1PeOaOlTGSjrikZ75z/hbox0am84t6AxI8Oo6A9N/XPNQogzTbQvzskQM1Z2dlu 7XQDD8yKq5ToP0S7lUk45InjQAJfchNugNS0qWK1MR5H0mdOrPvtJ2u9Obz2dLxGZl FijN/dfpEd44/lSsjQ3hZFP8MT068VAIj9rEpFXkqKdr5UxUEPhecasl7RtyfCY4lD AAJwlCV+A3gvG8tg+pfaHmbgi0EXsDBIiDb1hLpeLnWfRVs/2pMnMYrCl0qxGjYrev VTQRuuYUQY4Rw== From: Sasha Levin To: stable@vger.kernel.org Cc: Srujana Challa , "Michael S. Tsirkin" , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6.y] virtio_net: clamp rss_max_key_size to NETDEV_RSS_KEY_LEN Date: Wed, 8 Apr 2026 09:39:21 -0400 Message-ID: <20260408133921.1094528-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026040856-until-anybody-3769@gregkh> References: <2026040856-until-anybody-3769@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Srujana Challa [ Upstream commit b4e5f04c58a29c499faa85d12952ca9a4faf1cb9 ] rss_max_key_size in the virtio spec is the maximum key size supported by the device, not a mandatory size the driver must use. Also the value 40 is a spec minimum, not a spec maximum. The current code rejects RSS and can fail probe when the device reports a larger rss_max_key_size than the driver buffer limit. Instead, clamp the effective key length to min(device rss_max_key_size, NETDEV_RSS_KEY_LEN) and keep RSS enabled. This keeps probe working on devices that advertise larger maximum key sizes while respecting the netdev RSS key buffer size limit. Fixes: 3f7d9c1964fc ("virtio_net: Add hash_key_length check") Cc: stable@vger.kernel.org Signed-off-by: Srujana Challa Acked-by: Michael S. Tsirkin Link: https://patch.msgid.link/20260326142344.1171317-1-schalla@marvell.com Signed-off-by: Jakub Kicinski [ changed clamp target from NETDEV_RSS_KEY_LEN to VIRTIO_NET_RSS_MAX_KEY_SIZE ] Signed-off-by: Sasha Levin --- drivers/net/virtio_net.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index b33fc94ebd772..33f61922c1399 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -4465,6 +4465,7 @@ static int virtnet_probe(struct virtio_device *vdev) struct virtnet_info *vi; u16 max_queue_pairs; int mtu = 0; + u16 key_sz; /* Find if host supports multiqueue/rss virtio_net device */ max_queue_pairs = 1; @@ -4589,14 +4590,13 @@ static int virtnet_probe(struct virtio_device *vdev) } if (vi->has_rss || vi->has_rss_hash_report) { - vi->rss_key_size = - virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size)); - if (vi->rss_key_size > VIRTIO_NET_RSS_MAX_KEY_SIZE) { - dev_err(&vdev->dev, "rss_max_key_size=%u exceeds the limit %u.\n", - vi->rss_key_size, VIRTIO_NET_RSS_MAX_KEY_SIZE); - err = -EINVAL; - goto free; - } + key_sz = virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size)); + + vi->rss_key_size = min_t(u16, key_sz, VIRTIO_NET_RSS_MAX_KEY_SIZE); + if (key_sz > vi->rss_key_size) + dev_warn(&vdev->dev, + "rss_max_key_size=%u exceeds driver limit %u, clamping\n", + key_sz, vi->rss_key_size); vi->rss_hash_types_supported = virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types)); -- 2.53.0