diff options
| author | Andres Beltran <lkmlabelt@gmail.com> | 2020-11-09 11:04:00 +0100 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2020-11-17 10:51:06 +0000 |
| commit | e8b7db38449ac5b950a3f00519171c4be3e226ff (patch) | |
| tree | 257903993b84723c09238c6963d022a9d857520f /include/linux/hyperv.h | |
| parent | 09162bc32c880a791c6c0668ce0745cf7958f576 (diff) | |
Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening
Currently, VMbus drivers use pointers into guest memory as request IDs
for interactions with Hyper-V. To be more robust in the face of errors
or malicious behavior from a compromised Hyper-V, avoid exposing
guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a
bad request ID that is then treated as the address of a guest data
structure with no validation. Instead, encapsulate these memory
addresses and provide small integers as request IDs.
Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20201109100402.8946-2-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'include/linux/hyperv.h')
| -rw-r--r-- | include/linux/hyperv.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 1ce131f29f3b..5b6d5c4e3711 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -764,6 +764,22 @@ enum vmbus_device_type { HV_UNKNOWN, }; +/* + * Provides request ids for VMBus. Encapsulates guest memory + * addresses and stores the next available slot in req_arr + * to generate new ids in constant time. + */ +struct vmbus_requestor { + u64 *req_arr; + unsigned long *req_bitmap; /* is a given slot available? */ + u32 size; + u64 next_request_id; + spinlock_t req_lock; /* provides atomicity */ +}; + +#define VMBUS_NO_RQSTOR U64_MAX +#define VMBUS_RQST_ERROR (U64_MAX - 1) + struct vmbus_device { u16 dev_type; guid_t guid; @@ -988,8 +1004,14 @@ struct vmbus_channel { u32 fuzz_testing_interrupt_delay; u32 fuzz_testing_message_delay; + /* request/transaction ids for VMBus */ + struct vmbus_requestor requestor; + u32 rqstor_size; }; +u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr); +u64 vmbus_request_addr(struct vmbus_requestor *rqstor, u64 trans_id); + static inline bool is_hvsock_channel(const struct vmbus_channel *c) { return !!(c->offermsg.offer.chn_flags & |