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 CA53E27979A; Wed, 8 Apr 2026 18:37:26 +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=1775673446; cv=none; b=hcd6qxLo+xyvsmgCIwg4HXI8WGJc0Df8S6B9qossTJC19O3UVSDJUvNLVGu23R4Pvj7b4S96HCJRWhjpNz+OcQCltHbCCHXojqhjfFoPe4ol4vACe8iQNJOL4DNfRLIEm/TLmeMUCQJ9YjN2dm5dJP9JpzK867m7sva4nbMrkzs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775673446; c=relaxed/simple; bh=abNVh3+9x4fyjIF2hOtKeEjN1e9cj/4CRgmm/bCMEH0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ldWCYZWeYKa9YnynUS6whqhRD6PI9sZrUMhztT+zqA/wGyfaFZ/FcBRJbXUcO1fZpi0WyZ5J2CdDZYxpyfTSL/aC/EXeBiFuzZO/wVWSO0ciKfA24gpAS14k3kTLPmGqhLrY5cIRFUEHLummsHs8h6x4v3px5uRuPhuSaxWaJZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rJtkPOKj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rJtkPOKj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60B81C19421; Wed, 8 Apr 2026 18:37:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775673446; bh=abNVh3+9x4fyjIF2hOtKeEjN1e9cj/4CRgmm/bCMEH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rJtkPOKj8oPbiqYoJV+MtcR80AKC2T5zP9SpK01QIj6XsWemjjLMYaAxCuxWSCoip 0Tl0+xtMsD+mM6Zm3mL1TLyovC7Dcw22NMkFghUpQmWvYJi08vivH3rCAekqG2CL8O yk1KJNMBwy2MPvU9jFkBHhjeMHD1JOHn6iN8UDu0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Srujana Challa , "Michael S. Tsirkin" , Jakub Kicinski Subject: [PATCH 6.18 235/277] virtio_net: clamp rss_max_key_size to NETDEV_RSS_KEY_LEN Date: Wed, 8 Apr 2026 20:03:40 +0200 Message-ID: <20260408175942.632962273@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175933.836769063@linuxfoundation.org> References: <20260408175933.836769063@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Srujana Challa commit b4e5f04c58a29c499faa85d12952ca9a4faf1cb9 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/net/virtio_net.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -381,8 +381,6 @@ struct receive_queue { struct xdp_buff **xsk_buffs; }; -#define VIRTIO_NET_RSS_MAX_KEY_SIZE 40 - /* Control VQ buffers: protected by the rtnl lock */ struct control_buf { struct virtio_net_ctrl_hdr hdr; @@ -495,7 +493,7 @@ struct virtnet_info { /* Must be last as it ends in a flexible-array member. */ TRAILING_OVERLAP(struct virtio_net_rss_config_trailer, rss_trailer, hash_key_data, - u8 rss_hash_key_data[VIRTIO_NET_RSS_MAX_KEY_SIZE]; + u8 rss_hash_key_data[NETDEV_RSS_KEY_LEN]; ); }; static_assert(offsetof(struct virtnet_info, rss_trailer.hash_key_data) == @@ -6794,6 +6792,7 @@ static int virtnet_probe(struct virtio_d 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; @@ -6929,14 +6928,13 @@ static int virtnet_probe(struct virtio_d } 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, NETDEV_RSS_KEY_LEN); + 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));