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| author | Andrea Parri (Microsoft) <parri.andrea@gmail.com> | 2021-03-01 19:25:30 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-03-01 15:30:52 -0800 |
| commit | 3946688edbc5b629110c339b3babf10aa9e7adad (patch) | |
| tree | b72e021c1b857c4407f941010280e78d6296b573 /drivers/net/hyperv/netvsc_drv.c | |
| parent | 9200f515c41f4cbaeffd8fdd1d8b6373a18b1b67 (diff) | |
| download | lwn-3946688edbc5b629110c339b3babf10aa9e7adad.tar.gz lwn-3946688edbc5b629110c339b3babf10aa9e7adad.zip | |
hv_netvsc: Fix validation in netvsc_linkstatus_callback()
Contrary to the RNDIS protocol specification, certain (pre-Fe)
implementations of Hyper-V's vSwitch did not account for the status
buffer field in the length of an RNDIS packet; the bug was fixed in
newer implementations. Validate the status buffer fields using the
length of the 'vmtransfer_page' packet (all implementations), that
is known/validated to be less than or equal to the receive section
size and not smaller than the length of the RNDIS message.
Reported-by: Dexuan Cui <decui@microsoft.com>
Suggested-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Fixes: 505e3f00c3f36 ("hv_netvsc: Add (more) validation for untrusted Hyper-V values")
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/hyperv/netvsc_drv.c')
| -rw-r--r-- | drivers/net/hyperv/netvsc_drv.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 8176fa0c8b16..15f262b70489 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -744,7 +744,7 @@ static netdev_tx_t netvsc_start_xmit(struct sk_buff *skb, */ void netvsc_linkstatus_callback(struct net_device *net, struct rndis_message *resp, - void *data) + void *data, u32 data_buflen) { struct rndis_indicate_status *indicate = &resp->msg.indicate_status; struct net_device_context *ndev_ctx = netdev_priv(net); @@ -765,11 +765,16 @@ void netvsc_linkstatus_callback(struct net_device *net, if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) { u32 speed; - /* Validate status_buf_offset */ + /* Validate status_buf_offset and status_buflen. + * + * Certain (pre-Fe) implementations of Hyper-V's vSwitch didn't account + * for the status buffer field in resp->msg_len; perform the validation + * using data_buflen (>= resp->msg_len). + */ if (indicate->status_buflen < sizeof(speed) || indicate->status_buf_offset < sizeof(*indicate) || - resp->msg_len - RNDIS_HEADER_SIZE < indicate->status_buf_offset || - resp->msg_len - RNDIS_HEADER_SIZE - indicate->status_buf_offset + data_buflen - RNDIS_HEADER_SIZE < indicate->status_buf_offset || + data_buflen - RNDIS_HEADER_SIZE - indicate->status_buf_offset < indicate->status_buflen) { netdev_err(net, "invalid rndis_indicate_status packet\n"); return; |