Hi Andres, On Tue, Jun 30, 2020 at 08:12:20PM -0400, Andres Beltran wrote: > Currently, pointers to guest memory are passed to Hyper-V as > transaction IDs in storvsc. In the face of errors or malicious > behavior in Hyper-V, storvsc should not expose or trust the transaction > IDs returned by Hyper-V to be valid guest memory addresses. Instead, > use small integers generated by vmbus_requestor as requests > (transaction) IDs. > > Cc: "James E.J. Bottomley" <[email protected]> > Cc: "Martin K. Petersen" <[email protected]> > Cc: [email protected] > Signed-off-by: Andres Beltran <[email protected]> > Reviewed-by: Michael Kelley <[email protected]> > --- > Changes in v2: > - Add casts to unsigned long to fix warnings on 32bit. > > drivers/scsi/storvsc_drv.c | 85 +++++++++++++++++++++++++++++++++----- > 1 file changed, 74 insertions(+), 11 deletions(-) > > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c > index 624467e2590a..6d2df1f0fe6d 100644 > --- a/drivers/scsi/storvsc_drv.c > +++ b/drivers/scsi/storvsc_drv.c > @@ -399,6 +399,7 @@ static int storvsc_timeout = 180; > static struct scsi_transport_template *fc_transport_template; > #endif > > +static struct scsi_host_template scsi_driver; > static void storvsc_on_channel_callback(void *context); > > #define STORVSC_MAX_LUNS_PER_TARGET 255 > @@ -698,6 +699,12 @@ static void handle_sc_creation(struct vmbus_channel > *new_sc) > > memset(&props, 0, sizeof(struct vmstorage_channel_properties)); > > + /* > + * The size of vmbus_requestor is an upper bound on the number of > requests > + * that can be in-progress at any one time across all channels. > + */ > + new_sc->rqstor_size = scsi_driver.can_queue; > + > ret = vmbus_open(new_sc, > storvsc_ringbuffer_size, > storvsc_ringbuffer_size, > @@ -726,6 +733,7 @@ static void handle_multichannel_storage(struct hv_device > *device, int max_chns) > struct storvsc_cmd_request *request; > struct vstor_packet *vstor_packet; > int ret, t; > + u64 rqst_id; > > /* > * If the number of CPUs is artificially restricted, such as > @@ -760,14 +768,23 @@ static void handle_multichannel_storage(struct > hv_device *device, int max_chns) > vstor_packet->flags = REQUEST_COMPLETION_FLAG; > vstor_packet->sub_channel_count = num_sc; > > + rqst_id = vmbus_next_request_id(&device->channel->requestor, > + (unsigned long)request); > + if (rqst_id == VMBUS_RQST_ERROR) { > + dev_err(dev, "No request id available\n"); > + return; > + } > + > ret = vmbus_sendpacket(device->channel, vstor_packet, > (sizeof(struct vstor_packet) - > vmscsi_size_delta), > - (unsigned long)request, > + rqst_id, > VM_PKT_DATA_INBAND, > VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); > > if (ret != 0) { > + /* Reclaim request ID to avoid leak of IDs */ > + vmbus_request_addr(&device->channel->requestor, rqst_id); > dev_err(dev, "Failed to create sub-channel: err=%d\n", ret); > return; > } > @@ -818,20 +835,31 @@ static int storvsc_execute_vstor_op(struct hv_device > *device, > { > struct vstor_packet *vstor_packet; > int ret, t; > + u64 rqst_id; > > vstor_packet = &request->vstor_packet; > > init_completion(&request->wait_event); > vstor_packet->flags = REQUEST_COMPLETION_FLAG; > > + rqst_id = vmbus_next_request_id(&device->channel->requestor, > + (unsigned long)request); > + if (rqst_id == VMBUS_RQST_ERROR) { > + dev_err(&device->device, "No request id available\n"); > + return -EAGAIN; > + } > + > ret = vmbus_sendpacket(device->channel, vstor_packet, > (sizeof(struct vstor_packet) - > vmscsi_size_delta), > - (unsigned long)request, > + rqst_id, > VM_PKT_DATA_INBAND, > VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); > - if (ret != 0) > + if (ret != 0) { > + /* Reclaim request ID to avoid leak of IDs */ > + vmbus_request_addr(&device->channel->requestor, rqst_id); > return ret; > + } > > t = wait_for_completion_timeout(&request->wait_event, 5*HZ); > if (t == 0) > @@ -1233,9 +1261,17 @@ static void storvsc_on_channel_callback(void *context) > foreach_vmbus_pkt(desc, channel) { > void *packet = hv_pkt_data(desc); > struct storvsc_cmd_request *request; > + u64 cmd_rqst; > > - request = (struct storvsc_cmd_request *) > - ((unsigned long)desc->trans_id); > + cmd_rqst = vmbus_request_addr(&channel->requestor, > + desc->trans_id); > + if (cmd_rqst == VMBUS_RQST_ERROR) { > + dev_err(&device->device, > + "Incorrect transaction id\n"); > + continue; > + } > + > + request = (struct storvsc_cmd_request *)(unsigned long)cmd_rqst; > > if (request == &stor_device->init_request || > request == &stor_device->reset_request) { > @@ -1256,6 +1292,12 @@ static int storvsc_connect_to_vsp(struct hv_device > *device, u32 ring_size, > > memset(&props, 0, sizeof(struct vmstorage_channel_properties)); > > + /* > + * The size of vmbus_requestor is an upper bound on the number of > requests > + * that can be in-progress at any one time across all channels. > + */ > + device->channel->rqstor_size = scsi_driver.can_queue; > + > ret = vmbus_open(device->channel, > ring_size, > ring_size, > @@ -1369,6 +1411,7 @@ static int storvsc_do_io(struct hv_device *device, > int ret = 0; > const struct cpumask *node_mask; > int tgt_cpu; > + u64 rqst_id; > > vstor_packet = &request->vstor_packet; > stor_device = get_out_stor_device(device); > @@ -1463,6 +1506,13 @@ static int storvsc_do_io(struct hv_device *device, > > vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB; > > + rqst_id = vmbus_next_request_id(&outgoing_channel->requestor, > + (unsigned long)request); > + if (rqst_id == VMBUS_RQST_ERROR) { > + dev_err(&device->device, "No request id available\n"); > + return -EAGAIN; > + } > + > if (request->payload->range.len) { > > ret = vmbus_sendpacket_mpb_desc(outgoing_channel, > @@ -1470,18 +1520,21 @@ static int storvsc_do_io(struct hv_device *device, > vstor_packet, > (sizeof(struct vstor_packet) - > vmscsi_size_delta), > - (unsigned long)request); > + rqst_id); > } else { > ret = vmbus_sendpacket(outgoing_channel, vstor_packet, > (sizeof(struct vstor_packet) - > vmscsi_size_delta), > - (unsigned long)request, > + rqst_id, > VM_PKT_DATA_INBAND, > VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); > } > > - if (ret != 0) > + if (ret != 0) { > + /* Reclaim request ID to avoid leak of IDs */ > + vmbus_request_addr(&outgoing_channel->requestor, rqst_id); > return ret; > + } > > atomic_inc(&stor_device->num_outstanding_req); > > @@ -1562,7 +1615,7 @@ static int storvsc_host_reset_handler(struct scsi_cmnd > *scmnd) > struct storvsc_cmd_request *request; > struct vstor_packet *vstor_packet; > int ret, t; > - > + u64 rqst_id; > > stor_device = get_out_stor_device(device); > if (!stor_device) > @@ -1577,14 +1630,24 @@ static int storvsc_host_reset_handler(struct > scsi_cmnd *scmnd) > vstor_packet->flags = REQUEST_COMPLETION_FLAG; > vstor_packet->vm_srb.path_id = stor_device->path_id; > > + rqst_id = vmbus_next_request_id(&device->channel->requestor, > + (unsigned > long)&stor_device->reset_request); > + if (rqst_id == VMBUS_RQST_ERROR) { > + dev_err(&device->device, "No request id available\n"); > + return FAILED; > + } > + > ret = vmbus_sendpacket(device->channel, vstor_packet, > (sizeof(struct vstor_packet) - > vmscsi_size_delta), > - (unsigned long)&stor_device->reset_request, > + rqst_id, > VM_PKT_DATA_INBAND, > VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); > - if (ret != 0) > + if (ret != 0) { > + /* Reclaim request ID to avoid leak of IDs */ > + vmbus_request_addr(&device->channel->requestor, rqst_id); > return FAILED; > + } > > t = wait_for_completion_timeout(&request->wait_event, 5*HZ); > if (t == 0) > -- > 2.25.1 >
This patch has landed in linux-next as of next-20200707 and now I can no longer boot the WSL2 lightweight VM. PS C:\Users\natec> wsl -d ubuntu The virtual machine or container was forcefully exited. $ git bisect log # bad: [5b2a702f85b3285fcde0309aadacc13a36c70fc7] Add linux-next specific files for 20200707 # good: [bfe91da29bfad9941d5d703d45e29f0812a20724] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm git bisect start 'origin/master' 'origin/stable' # good: [885913a4d03f7f5fbd2c75121ea8c42f58185cc5] Merge remote-tracking branch 'crypto/master' git bisect good 885913a4d03f7f5fbd2c75121ea8c42f58185cc5 # good: [4a902a00a463f60b1630577a32e142800707c576] Merge remote-tracking branch 'regulator/for-next' git bisect good 4a902a00a463f60b1630577a32e142800707c576 # good: [e48c950eb83e19d532ea49112211b01c6210377a] Merge remote-tracking branch 'thunderbolt/next' git bisect good e48c950eb83e19d532ea49112211b01c6210377a # good: [0a299abc3a2127d9711517904a1e5c751985b5a5] Merge remote-tracking branch 'rtc/rtc-next' git bisect good 0a299abc3a2127d9711517904a1e5c751985b5a5 # good: [6de62f5629875029fbd8d79d7fa9c45e8dbea966] kcov: make some symbols static git bisect good 6de62f5629875029fbd8d79d7fa9c45e8dbea966 # bad: [9103b615924bf7594a7651a9777e0cf177201dbd] Merge remote-tracking branch 'auxdisplay/auxdisplay' git bisect bad 9103b615924bf7594a7651a9777e0cf177201dbd # good: [ed0e825a5c0f00aec12f79e8aef4b37dbb5a94f1] Merge remote-tracking branch 'kspp/for-next/kspp' git bisect good ed0e825a5c0f00aec12f79e8aef4b37dbb5a94f1 # good: [563bebf9d7625b579a13b79a4981fdd3097d9bce] Merge remote-tracking branch 'nvmem/for-next' git bisect good 563bebf9d7625b579a13b79a4981fdd3097d9bce # good: [efd8e353a542e79995681d98a4849eeeb1ce3809] Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening git bisect good efd8e353a542e79995681d98a4849eeeb1ce3809 # good: [27586ca786a729cda6c807621a1494900a56e7bc] XArray: Handle retry entries within xas_find_marked git bisect good 27586ca786a729cda6c807621a1494900a56e7bc # bad: [11478f56f20e3be6d11043b501f3090375af4492] hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening git bisect bad 11478f56f20e3be6d11043b501f3090375af4492 # bad: [8e569d774e1e73afabf1fbf40d11fcb8462ddffa] scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardeninggit bisect bad 8e569d774e1e73afabf1fbf40d11fcb8462ddffa # first bad commit: [8e569d774e1e73afabf1fbf40d11fcb8462ddffa] scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening If I revert this commit, everything works fine: PS C:\Users\natec> wsl --shutdown PS C:\Users\natec> wsl -d ubuntu -- /bin/bash nathan@Ryzen-9-3900X:/mnt/c/Users/natec$ cat /proc/version Linux version 5.8.0-rc4-next-20200707-microsoft-standard+ (nathan@Ryzen-9-3900X) (gcc (Ubuntu 9.3.0-10ubuntu2) 9.3.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #1 SMP Tue Jul 7 16:35:06 MST 2020 nathan@Ryzen-9-3900X:/mnt/c/Users/natec$ git -C ~/src/linux-next lo -2 0ff017dff922 (HEAD -> master) Revert "scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening" 5b2a702f85b3 (tag: next-20200707, origin/master, origin/HEAD) Add linux-next specific files for 20200707 nathan@Ryzen-9-3900X:/mnt/c/Users/natec$ The kernel was built using the following commands: $ mkdir -p out/x86_64 $ curl -LSso out/x86_64/.config https://github.com/microsoft/WSL2-Linux-Kernel/raw/linux-msft-wsl-4.19.y/Microsoft/config-wsl $ scripts/config --file out/x86_64/.config -d RAID6_PQ_BENCHMARK -e NET_9P_VIRTIO $ make -skj"$(nproc)" O=out/x86_64 olddefconfig bzImage I don't really know how to get more information than this as WSL seems rather opaque but I am happy to provide any information. Cheers, Nathan
