From: Stefano Garzarella On 32-bit architectures, both skb_queue_len() and SKB_TRUESIZE(0) evaluate to 32-bit values. The multiplication can overflow before being assigned to the u64 skb_overhead variable, making the skb overhead check ineffective. Cast skb_queue_len() to u64 so the multiplication is always performed in 64-bit arithmetic. This issue was reported by Sashiko while reviewing another patch. Fixes: 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue") Closes: https://sashiko.dev/#/patchset/20260518090656.134588-1-sgarzare%40redhat.com Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella --- net/vmw_vsock/virtio_transport_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index df3b418e0392..71198bf23fc4 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -417,7 +417,7 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) { - u64 skb_overhead = (skb_queue_len(&vvs->rx_queue) + 1) * SKB_TRUESIZE(0); + u64 skb_overhead = ((u64)skb_queue_len(&vvs->rx_queue) + 1) * SKB_TRUESIZE(0); /* Allow at most buf_alloc * 2 total budget (payload + overhead), * similar to how SO_RCVBUF is doubled to reserve space for sk_buff -- 2.54.0