17 Commits

Author SHA1 Message Date
Rijo Thomas
da7ce52a2f tee: amdtee: fix use-after-free vulnerability in amdtee_close_session
commit f4384b3e54ea813868bb81a861bf5b2406e15d8f upstream.

There is a potential race condition in amdtee_close_session that may
cause use-after-free in amdtee_open_session. For instance, if a session
has refcount == 1, and one thread tries to free this session via:

    kref_put(&sess->refcount, destroy_session);

the reference count will get decremented, and the next step would be to
call destroy_session(). However, if in another thread,
amdtee_open_session() is called before destroy_session() has completed
execution, alloc_session() may return 'sess' that will be freed up
later in destroy_session() leading to use-after-free in
amdtee_open_session.

To fix this issue, treat decrement of sess->refcount and removal of
'sess' from session list in destroy_session() as a critical section, so
that it is executed atomically.

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Cc: stable@vger.kernel.org
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-25 11:54:16 +02:00
Rijo Thomas
f632a90f8e tee: amdtee: fix race condition in amdtee_open_session
commit f8502fba45bd30e1a6a354d9d898bc99d1a11e6d upstream.

There is a potential race condition in amdtee_open_session that may
lead to use-after-free. For instance, in amdtee_open_session() after
sess->sess_mask is set, and before setting:

    sess->session_info[i] = session_info;

if amdtee_close_session() closes this same session, then 'sess' data
structure will be released, causing kernel panic when 'sess' is
accessed within amdtee_open_session().

The solution is to set the bit sess->sess_mask as the last step in
amdtee_open_session().

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Cc: stable@vger.kernel.org
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 11:23:41 +02:00
Dan Carpenter
640e28d618 tee: amdtee: fix an IS_ERR() vs NULL bug
[ Upstream commit 9d7482771fac8d8e38e763263f2ca0ca12dd22c6 ]

The __get_free_pages() function does not return error pointers it returns
NULL so fix this condition to avoid a NULL dereference.

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:30:52 +01:00
Rijo Thomas
c39a190d83 tee: amdtee: unload TA only when its refcount becomes 0
[ Upstream commit 9f015b3765bf593b3ed5d3b588e409dc0ffa9f85 ]

Same Trusted Application (TA) can be loaded in multiple TEE contexts.

If it is a single instance TA, the TA should not get unloaded from AMD
Secure Processor, while it is still in use in another TEE context.

Therefore reference count TA and unload it when the count becomes zero.

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Reviewed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-26 12:06:47 +02:00
Rijo Thomas
be353be278 tee: amdtee: synchronize access to shm list
Synchronize access to shm or shared memory buffer list to prevent
race conditions due to concurrent updates to shared shm list by
multiple threads.

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Reviewed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2020-11-09 08:59:00 +01:00
Rijo Thomas
ff1f855804 tee: amdtee: fix memory leak due to reset of global shm list
The driver maintains a list of shared memory buffers along with their
mapped buffer id's in a global linked list. These buffers need to be
unmapped after use by the user-space client.

The global shared memory list is initialized to zero entries in the
function amdtee_open(). This clearing of list entries can be a source
for memory leak on secure side if the global linked list previously
held some mapped buffer entries allocated from another TEE context.

Fix potential memory leak issue by moving global shared memory list
to AMD-TEE driver context data structure.

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Reviewed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2020-11-09 08:58:54 +01:00
Arnd Bergmann
47039b55f8 Merge tag 'tee-amdtee-fix2-for-5.6' of https://git.linaro.org/people/jens.wiklander/linux-tee into arm/fixes
tee: amdtee: out of bounds read in find_session()

* tag 'tee-amdtee-fix2-for-5.6' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  tee: amdtee: out of bounds read in find_session()

Link: https://lore.kernel.org/r/20200320063446.GA9892@jade
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-03-25 14:27:27 +01:00
Dan Carpenter
36fa3e5008 tee: amdtee: out of bounds read in find_session()
The "index" is a user provided value from 0-USHRT_MAX.  If it's over
TEE_NUM_SESSIONS (31) then it results in an out of bounds read when we
call test_bit(index, sess->sess_mask).

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Acked-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2020-03-10 08:12:04 +01:00
Dan Carpenter
b83685bcee tee: amdtee: fix memory leak in amdtee_open_session()
On these error paths the "sess" variable isn't freed.  It's a refcounted
pointer so we need to call kref_put().  I re-arranged the code a bit so
the error case is always handled before the success case and the error
paths are indented two tabs.

Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Reviewed-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2020-02-27 16:22:05 +01:00
Colin Ian King
48d625e4c4 tee: fix memory allocation failure checks on drv_data and amdtee
Currently the memory allocation failure checks on drv_data and
amdtee are using IS_ERR rather than checking for a null pointer.
Fix these checks to use the conventional null pointer check.

Addresses-Coverity: ("Dereference null return")
Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-22 16:21:11 +08:00
Rijo Thomas
279c075dc1 tee: amdtee: remove redundant NULL check for pool
Remove NULL check for pool variable, since in the current
code path it is guaranteed to be non-NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-16 15:18:14 +08:00
Rijo Thomas
f9568eae92 tee: amdtee: rename err label to err_device_unregister
Rename err label to err_device_unregister for better
readability.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-16 15:18:13 +08:00
Rijo Thomas
2929015535 tee: amdtee: skip tee_device_unregister if tee_device_alloc fails
Currently, if tee_device_alloc() fails, then tee_device_unregister()
is a no-op. Therefore, skip the function call to tee_device_unregister() by
introducing a new goto label 'err_free_pool'.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-16 15:18:13 +08:00
Rijo Thomas
f4c58c3758 tee: amdtee: print error message if tee not present
If there is no TEE with which the driver can communicate, then
print an error message and return.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-16 15:18:13 +08:00
Rijo Thomas
5ae63958a6 tee: amdtee: remove unused variable initialization
Remove unused variable initialization from driver code.

If enabled as a compiler option, compiler may throw warning for
unused assignments.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver")
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-16 15:18:13 +08:00
Rijo Thomas
bade7e1fbd tee: amdtee: check TEE status during driver initialization
The AMD-TEE driver should check if TEE is available before
registering itself with TEE subsystem. This ensures that
there is a TEE which the driver can talk to before proceeding
with tee device node allocation.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Reviewed-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-04 13:49:51 +08:00
Rijo Thomas
757cc3e9ff tee: add AMD-TEE driver
Adds AMD-TEE driver.
* targets AMD APUs which has AMD Secure Processor with software-based
  Trusted Execution Environment (TEE) support
* registers with TEE subsystem
* defines tee_driver_ops function callbacks
* kernel allocated memory is used as shared memory between normal
  world and secure world.
* acts as REE (Rich Execution Environment) communication agent, which
  uses the services of AMD Secure Processor driver to submit commands
  for processing in TEE environment

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Reviewed-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-04 13:49:51 +08:00