From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
To: KY Srinivasan <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Michael Kelley <mikelley@microsoft.com>,
Stefano Garzarella <sgarzare@redhat.com>,
David Miller <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: linux-hyperv@vger.kernel.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
"Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Subject: [PATCH v2 3/5] hv_sock: Add validation for untrusted Hyper-V values
Date: Wed, 27 Apr 2022 15:12:23 +0200 [thread overview]
Message-ID: <20220427131225.3785-4-parri.andrea@gmail.com> (raw)
In-Reply-To: <20220427131225.3785-1-parri.andrea@gmail.com>
For additional robustness in the face of Hyper-V errors or malicious
behavior, validate all values that originate from packets that Hyper-V
has sent to the guest in the host-to-guest ring buffer. Ensure that
invalid values cannot cause data being copied out of the bounds of the
source buffer in hvs_stream_dequeue().
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
---
include/linux/hyperv.h | 5 +++++
net/vmw_vsock/hyperv_transport.c | 10 ++++++++--
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index fe2e0179ed51e..55478a6810b60 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1663,6 +1663,11 @@ static inline u32 hv_pkt_datalen(const struct vmpacket_descriptor *desc)
return (desc->len8 << 3) - (desc->offset8 << 3);
}
+/* Get packet length associated with descriptor */
+static inline u32 hv_pkt_len(const struct vmpacket_descriptor *desc)
+{
+ return desc->len8 << 3;
+}
struct vmpacket_descriptor *
hv_pkt_iter_first_raw(struct vmbus_channel *channel);
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 8c37d07017fc4..fd98229e3db30 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -577,12 +577,18 @@ static bool hvs_dgram_allow(u32 cid, u32 port)
static int hvs_update_recv_data(struct hvsock *hvs)
{
struct hvs_recv_buf *recv_buf;
- u32 payload_len;
+ u32 pkt_len, payload_len;
+
+ pkt_len = hv_pkt_len(hvs->recv_desc);
+
+ if (pkt_len < HVS_HEADER_LEN)
+ return -EIO;
recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
payload_len = recv_buf->hdr.data_size;
- if (payload_len > HVS_MTU_SIZE)
+ if (payload_len > pkt_len - HVS_HEADER_LEN ||
+ payload_len > HVS_MTU_SIZE)
return -EIO;
if (payload_len == 0)
--
2.25.1
next prev parent reply other threads:[~2022-04-27 13:14 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-27 13:12 [PATCH v2 0/5] hv_sock: Hardening changes Andrea Parri (Microsoft)
2022-04-27 13:12 ` [PATCH v2 1/5] hv_sock: Check hv_pkt_iter_first_raw()'s return value Andrea Parri (Microsoft)
2022-04-27 13:12 ` [PATCH v2 2/5] hv_sock: Copy packets sent by Hyper-V out of the ring buffer Andrea Parri (Microsoft)
2022-04-27 13:38 ` Stefano Garzarella
2022-04-27 13:12 ` Andrea Parri (Microsoft) [this message]
2022-04-27 13:38 ` [PATCH v2 3/5] hv_sock: Add validation for untrusted Hyper-V values Stefano Garzarella
2022-04-27 13:12 ` [PATCH v2 4/5] Drivers: hv: vmbus: Accept hv_sock offers in isolated guests Andrea Parri (Microsoft)
2022-04-27 13:12 ` [PATCH v2 5/5] Drivers: hv: vmbus: Refactor the ring-buffer iterator functions Andrea Parri (Microsoft)
2022-04-28 14:22 ` [PATCH v2 0/5] hv_sock: Hardening changes Wei Liu
2022-04-28 14:56 ` Andrea Parri
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