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 5AE342627FC; Mon, 14 Jul 2025 15:21:15 +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=1752506475; cv=none; b=fSa5Kvq1bMZIYcXh1YG7n0z+ai0UhUDWzGBMZ3CV4yNcnLRDW89GaUbVgfFuAwVt/kgnMpzTSyrOGHjXnfVRPwFIwTeYLPRiqdTcTKihF+nKyRzKLq3DsyCivIlSLJOvBgzkTyVrP2KWq4neUrtYs7O/hQfZaL5+n7vmpGKT6nI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752506475; c=relaxed/simple; bh=iISDn9L+D3wVAHPNNIcp/TCqX/3WWeX/S60myFyZsyQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fMhqXtVCahyKYTjYBtN+0DhSX/wicKEzjtNzt8CFSI/oZaJzet9mpmwvglDsFaf0/HQ0qq4fckrlR8eQN//Q2sZXgISL7y35mYsZwpAKZSXvpzfE0/tdC52Agr0rTEDyT/Ha9WAKooZaRSOgqLm2uK6iFn1YUEo16RPYd+qOYiw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cU9/P+kD; 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="cU9/P+kD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E5BEC4CEF0; Mon, 14 Jul 2025 15:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752506474; bh=iISDn9L+D3wVAHPNNIcp/TCqX/3WWeX/S60myFyZsyQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cU9/P+kDTb3VLqs+GQ/BAkKRBw8CyTjCxzTm4rbVmE9cIWhZ4tsKrFOnsr/NQYfBB ybyjk5TUFAgVXnNH5DpiiB9cB9aiXnwWWyjwksYKFN8scGaawPY3rouhHjfngKZXl+ xAXw9D7iQh0nCLmI/e6D3/vW0qw+E6ZFx7vLFPmiAqMZpUvF3W5Gk4vexxtA/PEJZw S3/nPh1QtzuTAnr4ghzxr5/F32KE4W5EG9q5GWuJ+VArWqTPkBP/4LFSJAklps2/Fm UXucZZKDy20diWMOfEexVZv+Qhp7VlnBD7gSfyrBbOH4sNzQEq8rJQIU12aQ5/Szyt tJ1A+drGgRUoQ== From: Will Deacon To: linux-kernel@vger.kernel.org Cc: Will Deacon , Keir Fraser , Steven Moreland , Frederick Mayle , Stefan Hajnoczi , Stefano Garzarella , "Michael S. Tsirkin" , Jason Wang , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , netdev@vger.kernel.org, virtualization@lists.linux.dev, stable@vger.kernel.org Subject: [PATCH v3 1/9] vhost/vsock: Avoid allocating arbitrarily-sized SKBs Date: Mon, 14 Jul 2025 16:20:55 +0100 Message-Id: <20250714152103.6949-2-will@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250714152103.6949-1-will@kernel.org> References: <20250714152103.6949-1-will@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit vhost_vsock_alloc_skb() returns NULL for packets advertising a length larger than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE in the packet header. However, this is only checked once the SKB has been allocated and, if the length in the packet header is zero, the SKB may not be freed immediately. Hoist the size check before the SKB allocation so that an iovec larger than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + the header size is rejected outright. The subsequent check on the length field in the header can then simply check that the allocated SKB is indeed large enough to hold the packet. Cc: Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Signed-off-by: Will Deacon --- drivers/vhost/vsock.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 802153e23073..66a0f060770e 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -344,6 +344,9 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq, len = iov_length(vq->iov, out); + if (len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + VIRTIO_VSOCK_SKB_HEADROOM) + return NULL; + /* len contains both payload and hdr */ skb = virtio_vsock_alloc_skb(len, GFP_KERNEL); if (!skb) @@ -367,8 +370,7 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq, return skb; /* The pkt is too big or the length in the header is invalid */ - if (payload_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || - payload_len + sizeof(*hdr) > len) { + if (payload_len + sizeof(*hdr) > len) { kfree_skb(skb); return NULL; } -- 2.50.0.727.gbf7dc18ff4-goog