diff options
| author | Steven Price <steven.price@arm.com> | 2022-12-19 17:01:30 +0300 |
|---|---|---|
| committer | Steven Price <steven.price@arm.com> | 2022-12-21 18:04:42 +0300 |
| commit | 4217c6ac817451d5116687f3cc6286220dc43d49 (patch) | |
| tree | f615a26607d8077e1b5423f8715052032cf7ab10 /drivers/gpu/drm/panfrost/panfrost_gem.c | |
| parent | 4e699e34f923188175986ad8a74ab99f7034075e (diff) | |
| download | linux-4217c6ac817451d5116687f3cc6286220dc43d49.tar.xz | |
drm/panfrost: Fix GEM handle creation ref-counting
panfrost_gem_create_with_handle() previously returned a BO but with the
only reference being from the handle, which user space could in theory
guess and release, causing a use-after-free. Additionally if the call to
panfrost_gem_mapping_get() in panfrost_ioctl_create_bo() failed then
a(nother) reference on the BO was dropped.
The _create_with_handle() is a problematic pattern, so ditch it and
instead create the handle in panfrost_ioctl_create_bo(). If the call to
panfrost_gem_mapping_get() fails then this means that user space has
indeed gone behind our back and freed the handle. In which case just
return an error code.
Reported-by: Rob Clark <robdclark@chromium.org>
Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219140130.410578-1-steven.price@arm.com
Diffstat (limited to 'drivers/gpu/drm/panfrost/panfrost_gem.c')
| -rw-r--r-- | drivers/gpu/drm/panfrost/panfrost_gem.c | 16 |
1 files changed, 1 insertions, 15 deletions
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c index 293e799e2fe8..3c812fbd126f 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gem.c +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c @@ -235,12 +235,8 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t } struct panfrost_gem_object * -panfrost_gem_create_with_handle(struct drm_file *file_priv, - struct drm_device *dev, size_t size, - u32 flags, - uint32_t *handle) +panfrost_gem_create(struct drm_device *dev, size_t size, u32 flags) { - int ret; struct drm_gem_shmem_object *shmem; struct panfrost_gem_object *bo; @@ -256,16 +252,6 @@ panfrost_gem_create_with_handle(struct drm_file *file_priv, bo->noexec = !!(flags & PANFROST_BO_NOEXEC); bo->is_heap = !!(flags & PANFROST_BO_HEAP); - /* - * Allocate an id of idr table where the obj is registered - * and handle has the id what user can see. - */ - ret = drm_gem_handle_create(file_priv, &shmem->base, handle); - /* drop reference from allocate - handle holds it now. */ - drm_gem_object_put(&shmem->base); - if (ret) - return ERR_PTR(ret); - return bo; } |