Commit Graph

12 Commits

Author SHA1 Message Date
Jann Horn bb765d1c33 tee: shm: fix use-after-free via temporarily dropped reference
Bump the file's refcount before moving the reference into the fd table,
not afterwards. The old code could drop the file's refcount to zero for a
short moment before calling get_file() via get_dma_buf().

This code can only be triggered on ARM systems that use Linaro's OP-TEE.

Fixes: 967c9cca2c ("tee: generic TEE subsystem")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2018-05-07 11:50:25 +02:00
Dan Carpenter 2490cdf643 tee: shm: Potential NULL dereference calling tee_shm_register()
get_user_pages_fast() can return zero in certain error paths.  We should
handle that or else it means we accidentally return ERR_PTR(0) which is
NULL instead of an error pointer.  The callers are not expecting that
and will crash with a NULL dereference.

Fixes: 033ddf12bc ("tee: add register user memory")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2018-01-09 14:34:00 +01:00
Colin Ian King c94f31b526 tee: shm: don't put_page on null shm->pages
In the case that shm->pages fails to allocate, the current exit
error path will try to put_page on a null shm->pages and cause
a null pointer dereference when accessing shm->pages[n]. Fix this
by only performing the put_page and kfree on shm->pages if it
is not null.

Detected by CoverityScan, CID#1463283 ("Dereference after null check")

Fixes: 033ddf12bc ("tee: add register user memory")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-12-28 22:20:10 +01:00
Colin Ian King 80ec6f5de6 tee: shm: make function __tee_shm_alloc static
The function __tee_shm_alloc is local to the source and does
not need to be in global scope, so make it static.

Cleans up sparse warning:
symbol '__tee_shm_alloc' was not declared. Should it be static?

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-12-28 22:19:57 +01:00
Jens Wiklander 95ffe4ca43 tee: add start argument to shm_register callback
Adds a start argument to the shm_register callback to allow the callback
to check memory type of the passed pages.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-12-28 10:08:00 +01:00
Volodymyr Babchuk ef8e08d24c tee: shm: inline tee_shm_get_id()
Now, when struct tee_shm is defined in public header,
we can inline small getter functions like this one.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-12-15 13:36:21 +01:00
Volodymyr Babchuk 217e0250cc tee: use reference counting for tee_context
We need to ensure that tee_context is present until last
shared buffer will be freed.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-12-15 13:36:18 +01:00
Jens Wiklander 033ddf12bc tee: add register user memory
Added new ioctl to allow users register own buffers as a shared memory.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
[jw: moved tee_shm_is_registered() declaration]
[jw: added space after __tee_shm_alloc() implementation]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-12-15 13:32:20 +01:00
Jens Wiklander e2aca5d892 tee: flexible shared memory pool creation
Makes creation of shm pools more flexible by adding new more primitive
functions to allocate a shm pool. This makes it easier to add driver
specific shm pool management.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
2017-12-15 12:37:29 +01:00
Arvind Yadav 53e3ca5cee tee: tee_shm: Constify dma_buf_ops structures.
dma_buf_ops are not supposed to change at runtime. All functions
working with dma_buf_ops provided by <linux/dma-buf.h> work with
const dma_buf_ops. So mark the non-const structs as const.

File size before:
   text	   data	    bss	    dec	    hex	filename
   2026	    112	      0	   2138	    85a	drivers/tee/tee_shm.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
   2138	      0	      0	   2138	    85a	drivers/tee/tee_shm.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-08-04 10:30:27 +02:00
Linus Torvalds a2d9214c73 TEE driver infrastructure and OP-TEE drivers
This branch introduces a generic TEE framework in the kernel, to handle
 trusted environemtns (security coprocessor or software implementations
 such as OP-TEE/TrustZone). I'm sending it separately from the other
 arm-soc driver changes to give it a little more visibility, once
 the subsystem is merged, we will likely keep this in the arm₋soc
 drivers branch or have the maintainers submit pull requests directly,
 depending on the patch volume.
 
 I have reviewed earlier versions in the past, and have reviewed
 the latest version in person during Linaro Connect BUD17.
 
 Here is my overall assessment of the subsystem:
 
 * There is clearly demand for this, both for the generic
   infrastructure and the specific OP-TEE implementation.
 
 * The code has gone through a large number of reviews,
   and the review comments have all been addressed, but
   the reviews were not coming up with serious issues any more
   and nobody volunteered to vouch for the quality.
 
 * The user space ioctl interface is sufficient to work with the
   OP-TEE driver, and it should in principle work with other
   TEE implementations that follow the GlobalPlatform[1] standards,
   but it might need to be extended in minor ways depending on
   specific requirements of future TEE implementations
 
 * The main downside of the API to me is how the user space
   is tied to the TEE implementation in hardware or firmware,
   but uses a generic way to communicate with it. This seems
   to be an inherent problem with what it is trying to do,
   and I could not come up with any better solution than what
   is implemented here.
 
 For a detailed history of the patch series, see
 https://lkml.org/lkml/2017/3/10/1277
 
 Conflicts: needs a fixup after the drm tree was merged, see
 https://patchwork.kernel.org/patch/9691679/
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Merge tag 'armsoc-tee' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull TEE driver infrastructure and OP-TEE drivers from Arnd Bergmann:
 "This introduces a generic TEE framework in the kernel, to handle
  trusted environemtns (security coprocessor or software implementations
  such as OP-TEE/TrustZone). I'm sending it separately from the other
  arm-soc driver changes to give it a little more visibility, once the
  subsystem is merged, we will likely keep this in the arm₋soc drivers
  branch or have the maintainers submit pull requests directly,
  depending on the patch volume.

  I have reviewed earlier versions in the past, and have reviewed the
  latest version in person during Linaro Connect BUD17.

  Here is my overall assessment of the subsystem:

   - There is clearly demand for this, both for the generic
     infrastructure and the specific OP-TEE implementation.

   - The code has gone through a large number of reviews, and the review
     comments have all been addressed, but the reviews were not coming
     up with serious issues any more and nobody volunteered to vouch for
     the quality.

   - The user space ioctl interface is sufficient to work with the
     OP-TEE driver, and it should in principle work with other TEE
     implementations that follow the GlobalPlatform[1] standards, but it
     might need to be extended in minor ways depending on specific
     requirements of future TEE implementations

   - The main downside of the API to me is how the user space is tied to
     the TEE implementation in hardware or firmware, but uses a generic
     way to communicate with it. This seems to be an inherent problem
     with what it is trying to do, and I could not come up with any
     better solution than what is implemented here.

  For a detailed history of the patch series, see

    https://lkml.org/lkml/2017/3/10/1277"

* tag 'armsoc-tee' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: dt: hikey: Add optee node
  Documentation: tee subsystem and op-tee driver
  tee: add OP-TEE driver
  tee: generic TEE subsystem
  dt/bindings: add bindings for optee
2017-05-10 11:20:09 -07:00
Jens Wiklander 967c9cca2c tee: generic TEE subsystem
Initial patch for generic TEE subsystem.
This subsystem provides:
* Registration/un-registration of TEE drivers.
* Shared memory between normal world and secure world.
* Ioctl interface for interaction with user space.
* Sysfs implementation_id of TEE driver

A TEE (Trusted Execution Environment) driver is a driver that interfaces
with a trusted OS running in some secure environment, for example,
TrustZone on ARM cpus, or a separate secure co-processor etc.

The TEE subsystem can serve a TEE driver for a Global Platform compliant
TEE, but it's not limited to only Global Platform TEEs.

This patch builds on other similar implementations trying to solve
the same problem:
* "optee_linuxdriver" by among others
  Jean-michel DELORME<jean-michel.delorme@st.com> and
  Emmanuel MICHEL <emmanuel.michel@st.com>
* "Generic TrustZone Driver" by Javier González <javier@javigon.com>

Acked-by: Andreas Dannenberg <dannenberg@ti.com>
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey)
Tested-by: Volodymyr Babchuk <vlad.babchuk@gmail.com> (RCAR H3)
Tested-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-03-09 15:42:33 +01:00