| Message ID | 20220427131225.3785-4-parri.andrea@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | hv_sock: Hardening changes | expand |
On Wed, Apr 27, 2022 at 03:12:23PM +0200, Andrea Parri (Microsoft) wrote: >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 > Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
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)