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: [RFC PATCH 3/6] hv_sock: Add validation for untrusted Hyper-V values
Date: Wed, 13 Apr 2022 22:47:39 +0200 [thread overview]
Message-ID: <20220413204742.5539-4-parri.andrea@gmail.com> (raw)
In-Reply-To: <20220413204742.5539-1-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>
---
include/linux/hyperv.h | 5 +++++
net/vmw_vsock/hyperv_transport.c | 11 +++++++++--
2 files changed, 14 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..092cadc2c866d 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -577,12 +577,19 @@ 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);
+
+ /* Ensure the packet is big enough to read its header */
+ 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)
+ /* Ensure the packet is big enough to read its payload */
+ 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:[~2022-04-13 20:48 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-13 20:47 [RFC PATCH 0/6] hv_sock: Hardening changes Andrea Parri (Microsoft)
2022-04-13 20:47 ` [RFC PATCH 1/6] hv_sock: Check hv_pkt_iter_first_raw()'s return value Andrea Parri (Microsoft)
2022-04-15 3:33 ` Michael Kelley (LINUX)
2022-04-15 6:41 ` Andrea Parri
2022-04-15 14:27 ` Michael Kelley (LINUX)
2022-04-15 16:09 ` Andrea Parri
2022-04-13 20:47 ` [RFC PATCH 2/6] hv_sock: Copy packets sent by Hyper-V out of the ring buffer Andrea Parri (Microsoft)
2022-04-15 3:33 ` Michael Kelley (LINUX)
2022-04-15 6:42 ` Andrea Parri
2022-04-13 20:47 ` Andrea Parri (Microsoft) [this message]
2022-04-13 20:47 ` [RFC PATCH 4/6] hv_sock: Initialize send_buf in hvs_stream_enqueue() Andrea Parri (Microsoft)
2022-04-15 3:33 ` Michael Kelley (LINUX)
2022-04-15 6:50 ` Andrea Parri
2022-04-15 14:30 ` Michael Kelley (LINUX)
2022-04-15 16:16 ` Andrea Parri
2022-04-13 20:47 ` [RFC PATCH 5/6] Drivers: hv: vmbus: Accept hv_sock offers in isolated guests Andrea Parri (Microsoft)
2022-04-15 3:33 ` Michael Kelley (LINUX)
2022-04-15 6:58 ` Andrea Parri
2022-04-13 20:47 ` [RFC PATCH 6/6] Drivers: hv: vmbus: Refactor the ring-buffer iterator functions Andrea Parri (Microsoft)
2022-04-15 3:34 ` Michael Kelley (LINUX)
2022-04-15 7:00 ` Andrea Parri
2022-04-15 16:28 ` Andrea Parri
2022-04-15 16:44 ` Michael Kelley (LINUX)
2022-04-15 17:05 ` Andrea Parri
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