On Mon, Nov 09, 2020 at 11:07:04AM +0100, Andrea Parri (Microsoft) wrote:
> From: Andres Beltran <lkmlabelt@xxxxxxxxx>
>
> 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 indexing off the end of the icversion_data
> array in vmbus_prep_negotiate_resp().
>
> Signed-off-by: Andres Beltran <lkmlabelt@xxxxxxxxx>
> Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
Ping, other suggestions about this patch?
Thanks,
Andrea
> ---
> Changes in v3:
> - Add size check for icframe_vercnt and icmsg_vercnt
>
> Changes in v2:
> - Use ratelimited form of kernel logging to print error messages
>
> drivers/hv/channel_mgmt.c | 24 ++++-
> drivers/hv/hv_fcopy.c | 36 +++++--
> drivers/hv/hv_kvp.c | 122 ++++++++++++---------
> drivers/hv/hv_snapshot.c | 89 ++++++++-------
> drivers/hv/hv_util.c | 222 +++++++++++++++++++++++---------------
> include/linux/hyperv.h | 9 +-
> 6 files changed, 314 insertions(+), 188 deletions(-)
>
> diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
> index 1d44bb635bb84..5bc5eef5da159 100644
> --- a/drivers/hv/channel_mgmt.c
> +++ b/drivers/hv/channel_mgmt.c
> @@ -190,6 +190,7 @@ static u16 hv_get_dev_type(const struct vmbus_channel *channel)
> * vmbus_prep_negotiate_resp() - Create default response for Negotiate message
> * @icmsghdrp: Pointer to msg header structure
> * @buf: Raw buffer channel data
> + * @buflen: Length of the raw buffer channel data.
> * @fw_version: The framework versions we can support.
> * @fw_vercnt: The size of @fw_version.
> * @srv_version: The service versions we can support.
> @@ -202,8 +203,8 @@ static u16 hv_get_dev_type(const struct vmbus_channel *channel)
> * Set up and fill in default negotiate response message.
> * Mainly used by Hyper-V drivers.
> */
> -bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
> - u8 *buf, const int *fw_version, int fw_vercnt,
> +bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf,
> + u32 buflen, const int *fw_version, int fw_vercnt,
> const int *srv_version, int srv_vercnt,
> int *nego_fw_version, int *nego_srv_version)
> {
> @@ -215,10 +216,14 @@ bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
> bool found_match = false;
> struct icmsg_negotiate *negop;
>
> + /* Check that there's enough space for icframe_vercnt, icmsg_vercnt */
> + if (buflen < ICMSG_HDR + offsetof(struct icmsg_negotiate, reserved)) {
> + pr_err_ratelimited("Invalid icmsg negotiate\n");
> + return false;
> + }
> +
> icmsghdrp->icmsgsize = 0x10;
> - negop = (struct icmsg_negotiate *)&buf[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> + negop = (struct icmsg_negotiate *)&buf[ICMSG_HDR];
>
> icframe_major = negop->icframe_vercnt;
> icframe_minor = 0;
> @@ -226,6 +231,15 @@ bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
> icmsg_major = negop->icmsg_vercnt;
> icmsg_minor = 0;
>
> + /* Validate negop packet */
> + if (icframe_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
> + icmsg_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
> + ICMSG_NEGOTIATE_PKT_SIZE(icframe_major, icmsg_major) > buflen) {
> + pr_err_ratelimited("Invalid icmsg negotiate - icframe_major: %u, icmsg_major: %u\n",
> + icframe_major, icmsg_major);
> + goto fw_error;
> + }
> +
> /*
> * Select the framework version number we will
> * support.
> diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c
> index 5040d7e0cd9e9..59ce85e00a028 100644
> --- a/drivers/hv/hv_fcopy.c
> +++ b/drivers/hv/hv_fcopy.c
> @@ -235,15 +235,27 @@ void hv_fcopy_onchannelcallback(void *context)
> if (fcopy_transaction.state > HVUTIL_READY)
> return;
>
> - vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen,
> - &requestid);
> - if (recvlen <= 0)
> + if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen, &requestid)) {
> + pr_err_ratelimited("Fcopy request received. Could not read into recv buf\n");
> return;
> + }
> +
> + if (!recvlen)
> + return;
> +
> + /* Ensure recvlen is big enough to read header data */
> + if (recvlen < ICMSG_HDR) {
> + pr_err_ratelimited("Fcopy request received. Packet length too small: %d\n",
> + recvlen);
> + return;
> + }
>
> icmsghdr = (struct icmsg_hdr *)&recv_buffer[
> sizeof(struct vmbuspipe_hdr)];
> +
> if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> - if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
> + if (vmbus_prep_negotiate_resp(icmsghdr,
> + recv_buffer, recvlen,
> fw_versions, FW_VER_COUNT,
> fcopy_versions, FCOPY_VER_COUNT,
> NULL, &fcopy_srv_version)) {
> @@ -252,10 +264,14 @@ void hv_fcopy_onchannelcallback(void *context)
> fcopy_srv_version >> 16,
> fcopy_srv_version & 0xFFFF);
> }
> - } else {
> - fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> + } else if (icmsghdr->icmsgtype == ICMSGTYPE_FCOPY) {
> + /* Ensure recvlen is big enough to contain hv_fcopy_hdr */
> + if (recvlen < ICMSG_HDR + sizeof(struct hv_fcopy_hdr)) {
> + pr_err_ratelimited("Invalid Fcopy hdr. Packet length too small: %u\n",
> + recvlen);
> + return;
> + }
> + fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[ICMSG_HDR];
>
> /*
> * Stash away this global state for completing the
> @@ -280,6 +296,10 @@ void hv_fcopy_onchannelcallback(void *context)
> schedule_delayed_work(&fcopy_timeout_work,
> HV_UTIL_TIMEOUT * HZ);
> return;
> + } else {
> + pr_err_ratelimited("Fcopy request received. Invalid msg type: %d\n",
> + icmsghdr->icmsgtype);
> + return;
> }
> icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
> vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
> diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
> index 754d35a25a1cc..b49962d312cef 100644
> --- a/drivers/hv/hv_kvp.c
> +++ b/drivers/hv/hv_kvp.c
> @@ -662,71 +662,87 @@ void hv_kvp_onchannelcallback(void *context)
> if (kvp_transaction.state > HVUTIL_READY)
> return;
>
> - vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 4, &recvlen,
> - &requestid);
> -
> - if (recvlen > 0) {
> - icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
> - sizeof(struct vmbuspipe_hdr)];
> -
> - if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> - if (vmbus_prep_negotiate_resp(icmsghdrp,
> - recv_buffer, fw_versions, FW_VER_COUNT,
> - kvp_versions, KVP_VER_COUNT,
> - NULL, &kvp_srv_version)) {
> - pr_info("KVP IC version %d.%d\n",
> - kvp_srv_version >> 16,
> - kvp_srv_version & 0xFFFF);
> - }
> - } else {
> - kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> + if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 4, &recvlen, &requestid)) {
> + pr_err_ratelimited("KVP request received. Could not read into recv buf\n");
> + return;
> + }
>
> - /*
> - * Stash away this global state for completing the
> - * transaction; note transactions are serialized.
> - */
> + if (!recvlen)
> + return;
>
> - kvp_transaction.recv_len = recvlen;
> - kvp_transaction.recv_req_id = requestid;
> - kvp_transaction.kvp_msg = kvp_msg;
> + /* Ensure recvlen is big enough to read header data */
> + if (recvlen < ICMSG_HDR) {
> + pr_err_ratelimited("KVP request received. Packet length too small: %d\n",
> + recvlen);
> + return;
> + }
>
> - if (kvp_transaction.state < HVUTIL_READY) {
> - /* Userspace is not registered yet */
> - kvp_respond_to_host(NULL, HV_E_FAIL);
> - return;
> - }
> - kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
> + icmsghdrp = (struct icmsg_hdr *)&recv_buffer[sizeof(struct vmbuspipe_hdr)];
> +
> + if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> + if (vmbus_prep_negotiate_resp(icmsghdrp,
> + recv_buffer, recvlen,
> + fw_versions, FW_VER_COUNT,
> + kvp_versions, KVP_VER_COUNT,
> + NULL, &kvp_srv_version)) {
> + pr_info("KVP IC version %d.%d\n",
> + kvp_srv_version >> 16,
> + kvp_srv_version & 0xFFFF);
> + }
> + } else if (icmsghdrp->icmsgtype == ICMSGTYPE_KVPEXCHANGE) {
> + /*
> + * recvlen is not checked against sizeof(struct kvp_msg) because kvp_msg contains
> + * a union of structs and the msg type received is not known. Code using this
> + * struct should provide validation when accessing its fields.
> + */
> + kvp_msg = (struct hv_kvp_msg *)&recv_buffer[ICMSG_HDR];
>
> - /*
> - * Get the information from the
> - * user-mode component.
> - * component. This transaction will be
> - * completed when we get the value from
> - * the user-mode component.
> - * Set a timeout to deal with
> - * user-mode not responding.
> - */
> - schedule_work(&kvp_sendkey_work);
> - schedule_delayed_work(&kvp_timeout_work,
> - HV_UTIL_TIMEOUT * HZ);
> + /*
> + * Stash away this global state for completing the
> + * transaction; note transactions are serialized.
> + */
>
> - return;
> + kvp_transaction.recv_len = recvlen;
> + kvp_transaction.recv_req_id = requestid;
> + kvp_transaction.kvp_msg = kvp_msg;
>
> + if (kvp_transaction.state < HVUTIL_READY) {
> + /* Userspace is not registered yet */
> + kvp_respond_to_host(NULL, HV_E_FAIL);
> + return;
> }
> + kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
>
> - icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
> - | ICMSGHDRFLAG_RESPONSE;
> + /*
> + * Get the information from the
> + * user-mode component.
> + * component. This transaction will be
> + * completed when we get the value from
> + * the user-mode component.
> + * Set a timeout to deal with
> + * user-mode not responding.
> + */
> + schedule_work(&kvp_sendkey_work);
> + schedule_delayed_work(&kvp_timeout_work,
> + HV_UTIL_TIMEOUT * HZ);
>
> - vmbus_sendpacket(channel, recv_buffer,
> - recvlen, requestid,
> - VM_PKT_DATA_INBAND, 0);
> + return;
>
> - host_negotiatied = NEGO_FINISHED;
> - hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
> + } else {
> + pr_err_ratelimited("KVP request received. Invalid msg type: %d\n",
> + icmsghdrp->icmsgtype);
> + return;
> }
>
> + icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
> + | ICMSGHDRFLAG_RESPONSE;
> +
> + vmbus_sendpacket(channel, recv_buffer,
> + recvlen, requestid,
> + VM_PKT_DATA_INBAND, 0);
> +
> + host_negotiatied = NEGO_FINISHED;
> + hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
> }
>
> static void kvp_on_reset(void)
> diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
> index 783779e4cc1a5..2267bd4c34725 100644
> --- a/drivers/hv/hv_snapshot.c
> +++ b/drivers/hv/hv_snapshot.c
> @@ -298,49 +298,64 @@ void hv_vss_onchannelcallback(void *context)
> if (vss_transaction.state > HVUTIL_READY)
> return;
>
> - vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen,
> - &requestid);
> -
> - if (recvlen > 0) {
> - icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
> - sizeof(struct vmbuspipe_hdr)];
> -
> - if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> - if (vmbus_prep_negotiate_resp(icmsghdrp,
> - recv_buffer, fw_versions, FW_VER_COUNT,
> - vss_versions, VSS_VER_COUNT,
> - NULL, &vss_srv_version)) {
> -
> - pr_info("VSS IC version %d.%d\n",
> - vss_srv_version >> 16,
> - vss_srv_version & 0xFFFF);
> - }
> - } else {
> - vss_msg = (struct hv_vss_msg *)&recv_buffer[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> -
> - /*
> - * Stash away this global state for completing the
> - * transaction; note transactions are serialized.
> - */
> -
> - vss_transaction.recv_len = recvlen;
> - vss_transaction.recv_req_id = requestid;
> - vss_transaction.msg = (struct hv_vss_msg *)vss_msg;
> -
> - schedule_work(&vss_handle_request_work);
> + if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen, &requestid)) {
> + pr_err_ratelimited("VSS request received. Could not read into recv buf\n");
> + return;
> + }
> +
> + if (!recvlen)
> + return;
> +
> + /* Ensure recvlen is big enough to read header data */
> + if (recvlen < ICMSG_HDR) {
> + pr_err_ratelimited("VSS request received. Packet length too small: %d\n",
> + recvlen);
> + return;
> + }
> +
> + icmsghdrp = (struct icmsg_hdr *)&recv_buffer[sizeof(struct vmbuspipe_hdr)];
> +
> + if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> + if (vmbus_prep_negotiate_resp(icmsghdrp,
> + recv_buffer, recvlen,
> + fw_versions, FW_VER_COUNT,
> + vss_versions, VSS_VER_COUNT,
> + NULL, &vss_srv_version)) {
> +
> + pr_info("VSS IC version %d.%d\n",
> + vss_srv_version >> 16,
> + vss_srv_version & 0xFFFF);
> + }
> + } else if (icmsghdrp->icmsgtype == ICMSGTYPE_VSS) {
> + /* Ensure recvlen is big enough to contain hv_vss_msg */
> + if (recvlen < ICMSG_HDR + sizeof(struct hv_vss_msg)) {
> + pr_err_ratelimited("Invalid VSS msg. Packet length too small: %u\n",
> + recvlen);
> return;
> }
> + vss_msg = (struct hv_vss_msg *)&recv_buffer[ICMSG_HDR];
> +
> + /*
> + * Stash away this global state for completing the
> + * transaction; note transactions are serialized.
> + */
>
> - icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
> - | ICMSGHDRFLAG_RESPONSE;
> + vss_transaction.recv_len = recvlen;
> + vss_transaction.recv_req_id = requestid;
> + vss_transaction.msg = (struct hv_vss_msg *)vss_msg;
>
> - vmbus_sendpacket(channel, recv_buffer,
> - recvlen, requestid,
> - VM_PKT_DATA_INBAND, 0);
> + schedule_work(&vss_handle_request_work);
> + return;
> + } else {
> + pr_err_ratelimited("VSS request received. Invalid msg type: %d\n",
> + icmsghdrp->icmsgtype);
> + return;
> }
>
> + icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION |
> + ICMSGHDRFLAG_RESPONSE;
> + vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
> + VM_PKT_DATA_INBAND, 0);
> }
>
> static void vss_on_reset(void)
> diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
> index 05566ecdbe4b4..34f3e789cc9a2 100644
> --- a/drivers/hv/hv_util.c
> +++ b/drivers/hv/hv_util.c
> @@ -195,73 +195,88 @@ static void shutdown_onchannelcallback(void *context)
>
> struct icmsg_hdr *icmsghdrp;
>
> - vmbus_recvpacket(channel, shut_txf_buf,
> - HV_HYP_PAGE_SIZE, &recvlen, &requestid);
> + if (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
> + pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
> + return;
> + }
>
> - if (recvlen > 0) {
> - icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
> - sizeof(struct vmbuspipe_hdr)];
> + if (!recvlen)
> + return;
>
> - if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> - if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
> - fw_versions, FW_VER_COUNT,
> - sd_versions, SD_VER_COUNT,
> - NULL, &sd_srv_version)) {
> - pr_info("Shutdown IC version %d.%d\n",
> - sd_srv_version >> 16,
> - sd_srv_version & 0xFFFF);
> - }
> - } else {
> - shutdown_msg =
> - (struct shutdown_msg_data *)&shut_txf_buf[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> + /* Ensure recvlen is big enough to read header data */
> + if (recvlen < ICMSG_HDR) {
> + pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
> + recvlen);
> + return;
> + }
>
> - /*
> - * shutdown_msg->flags can be 0(shut down), 2(reboot),
> - * or 4(hibernate). It may bitwise-OR 1, which means
> - * performing the request by force. Linux always tries
> - * to perform the request by force.
> - */
> - switch (shutdown_msg->flags) {
> - case 0:
> - case 1:
> - icmsghdrp->status = HV_S_OK;
> - work = &shutdown_work;
> - pr_info("Shutdown request received -"
> - " graceful shutdown initiated\n");
> - break;
> - case 2:
> - case 3:
> - icmsghdrp->status = HV_S_OK;
> - work = &restart_work;
> - pr_info("Restart request received -"
> - " graceful restart initiated\n");
> - break;
> - case 4:
> - case 5:
> - pr_info("Hibernation request received\n");
> - icmsghdrp->status = hibernation_supported ?
> - HV_S_OK : HV_E_FAIL;
> - if (hibernation_supported)
> - work = &hibernate_context.work;
> - break;
> - default:
> - icmsghdrp->status = HV_E_FAIL;
> - pr_info("Shutdown request received -"
> - " Invalid request\n");
> - break;
> - }
> + icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[sizeof(struct vmbuspipe_hdr)];
> +
> + if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> + if (vmbus_prep_negotiate_resp(icmsghdrp,
> + shut_txf_buf, recvlen,
> + fw_versions, FW_VER_COUNT,
> + sd_versions, SD_VER_COUNT,
> + NULL, &sd_srv_version)) {
> + pr_info("Shutdown IC version %d.%d\n",
> + sd_srv_version >> 16,
> + sd_srv_version & 0xFFFF);
> + }
> + } else if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
> + /* Ensure recvlen is big enough to contain shutdown_msg_data struct */
> + if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
> + pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
> + recvlen);
> + return;
> }
>
> - icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
> - | ICMSGHDRFLAG_RESPONSE;
> -
> - vmbus_sendpacket(channel, shut_txf_buf,
> - recvlen, requestid,
> - VM_PKT_DATA_INBAND, 0);
> + shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];
> +
> + /*
> + * shutdown_msg->flags can be 0(shut down), 2(reboot),
> + * or 4(hibernate). It may bitwise-OR 1, which means
> + * performing the request by force. Linux always tries
> + * to perform the request by force.
> + */
> + switch (shutdown_msg->flags) {
> + case 0:
> + case 1:
> + icmsghdrp->status = HV_S_OK;
> + work = &shutdown_work;
> + pr_info("Shutdown request received - graceful shutdown initiated\n");
> + break;
> + case 2:
> + case 3:
> + icmsghdrp->status = HV_S_OK;
> + work = &restart_work;
> + pr_info("Restart request received - graceful restart initiated\n");
> + break;
> + case 4:
> + case 5:
> + pr_info("Hibernation request received\n");
> + icmsghdrp->status = hibernation_supported ?
> + HV_S_OK : HV_E_FAIL;
> + if (hibernation_supported)
> + work = &hibernate_context.work;
> + break;
> + default:
> + icmsghdrp->status = HV_E_FAIL;
> + pr_info("Shutdown request received - Invalid request\n");
> + break;
> + }
> + } else {
> + icmsghdrp->status = HV_E_FAIL;
> + pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
> + icmsghdrp->icmsgtype);
> }
>
> + icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
> + | ICMSGHDRFLAG_RESPONSE;
> +
> + vmbus_sendpacket(channel, shut_txf_buf,
> + recvlen, requestid,
> + VM_PKT_DATA_INBAND, 0);
> +
> if (work)
> schedule_work(work);
> }
> @@ -396,19 +411,27 @@ static void timesync_onchannelcallback(void *context)
> HV_HYP_PAGE_SIZE, &recvlen,
> &requestid);
> if (ret) {
> - pr_warn_once("TimeSync IC pkt recv failed (Err: %d)\n",
> - ret);
> + pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
> + ret);
> break;
> }
>
> if (!recvlen)
> break;
>
> + /* Ensure recvlen is big enough to read header data */
> + if (recvlen < ICMSG_HDR) {
> + pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
> + recvlen);
> + break;
> + }
> +
> icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
> sizeof(struct vmbuspipe_hdr)];
>
> if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> - if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
> + if (vmbus_prep_negotiate_resp(icmsghdrp,
> + time_txf_buf, recvlen,
> fw_versions, FW_VER_COUNT,
> ts_versions, TS_VER_COUNT,
> NULL, &ts_srv_version)) {
> @@ -416,33 +439,44 @@ static void timesync_onchannelcallback(void *context)
> ts_srv_version >> 16,
> ts_srv_version & 0xFFFF);
> }
> - } else {
> + } else if (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
> if (ts_srv_version > TS_VERSION_3) {
> - refdata = (struct ictimesync_ref_data *)
> - &time_txf_buf[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> + /* Ensure recvlen is big enough to read ictimesync_ref_data */
> + if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
> + pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
> + recvlen);
> + break;
> + }
> + refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];
>
> adj_guesttime(refdata->parenttime,
> refdata->vmreferencetime,
> refdata->flags);
> } else {
> - timedatap = (struct ictimesync_data *)
> - &time_txf_buf[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> + /* Ensure recvlen is big enough to read ictimesync_data */
> + if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
> + pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
> + recvlen);
> + break;
> + }
> + timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];
> +
> adj_guesttime(timedatap->parenttime,
> hv_read_reference_counter(),
> timedatap->flags);
> }
> + } else {
> + icmsghdrp->status = HV_E_FAIL;
> + pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
> + icmsghdrp->icmsgtype);
> }
>
> icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
> | ICMSGHDRFLAG_RESPONSE;
>
> vmbus_sendpacket(channel, time_txf_buf,
> - recvlen, requestid,
> - VM_PKT_DATA_INBAND, 0);
> + recvlen, requestid,
> + VM_PKT_DATA_INBAND, 0);
> }
> }
>
> @@ -462,18 +496,28 @@ static void heartbeat_onchannelcallback(void *context)
>
> while (1) {
>
> - vmbus_recvpacket(channel, hbeat_txf_buf,
> - HV_HYP_PAGE_SIZE, &recvlen, &requestid);
> + if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
> + &recvlen, &requestid)) {
> + pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
> + return;
> + }
>
> if (!recvlen)
> break;
>
> + /* Ensure recvlen is big enough to read header data */
> + if (recvlen < ICMSG_HDR) {
> + pr_err_ratelimited("Hearbeat request received. Packet length too small: %d\n",
> + recvlen);
> + break;
> + }
> +
> icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
> sizeof(struct vmbuspipe_hdr)];
>
> if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
> if (vmbus_prep_negotiate_resp(icmsghdrp,
> - hbeat_txf_buf,
> + hbeat_txf_buf, recvlen,
> fw_versions, FW_VER_COUNT,
> hb_versions, HB_VER_COUNT,
> NULL, &hb_srv_version)) {
> @@ -482,21 +526,31 @@ static void heartbeat_onchannelcallback(void *context)
> hb_srv_version >> 16,
> hb_srv_version & 0xFFFF);
> }
> - } else {
> - heartbeat_msg =
> - (struct heartbeat_msg_data *)&hbeat_txf_buf[
> - sizeof(struct vmbuspipe_hdr) +
> - sizeof(struct icmsg_hdr)];
> + } else if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
> + /*
> + * Ensure recvlen is big enough to read seq_num. Reserved area is not
> + * included in the check as the host may not fill it up entirely
> + */
> + if (recvlen < ICMSG_HDR + sizeof(u64)) {
> + pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
> + recvlen);
> + break;
> + }
> + heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];
>
> heartbeat_msg->seq_num += 1;
> + } else {
> + icmsghdrp->status = HV_E_FAIL;
> + pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
> + icmsghdrp->icmsgtype);
> }
>
> icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
> | ICMSGHDRFLAG_RESPONSE;
>
> vmbus_sendpacket(channel, hbeat_txf_buf,
> - recvlen, requestid,
> - VM_PKT_DATA_INBAND, 0);
> + recvlen, requestid,
> + VM_PKT_DATA_INBAND, 0);
> }
> }
>
> diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
> index 5ddb479c4d4cb..696857aa038c0 100644
> --- a/include/linux/hyperv.h
> +++ b/include/linux/hyperv.h
> @@ -1471,6 +1471,7 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size);
> #define ICMSGTYPE_SHUTDOWN 3
> #define ICMSGTYPE_TIMESYNC 4
> #define ICMSGTYPE_VSS 5
> +#define ICMSGTYPE_FCOPY 7
>
> #define ICMSGHDRFLAG_TRANSACTION 1
> #define ICMSGHDRFLAG_REQUEST 2
> @@ -1514,6 +1515,12 @@ struct icmsg_hdr {
> u8 reserved[2];
> } __packed;
>
> +#define IC_VERSION_NEGOTIATION_MAX_VER_COUNT 100
> +#define ICMSG_HDR (sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr))
> +#define ICMSG_NEGOTIATE_PKT_SIZE(icframe_vercnt, icmsg_vercnt) \
> + (ICMSG_HDR + offsetof(struct icmsg_negotiate, icversion_data) + \
> + (((icframe_vercnt) + (icmsg_vercnt)) * sizeof(struct ic_version)))
> +
> struct icmsg_negotiate {
> u16 icframe_vercnt;
> u16 icmsg_vercnt;
> @@ -1569,7 +1576,7 @@ struct hyperv_service_callback {
> };
>
> #define MAX_SRV_VER 0x7ffffff
> -extern bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf,
> +extern bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf, u32 buflen,
> const int *fw_version, int fw_vercnt,
> const int *srv_version, int srv_vercnt,
> int *nego_fw_version, int *nego_srv_version);
> --
> 2.25.1
>
