diff options
| author | Thomas Zimmermann <tzimmermann@suse.de> | 2025-07-15 17:58:17 +0200 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2025-07-17 12:26:19 +0200 |
| commit | 1918e79be908b8a2c8757640289bc196c14d928a (patch) | |
| tree | 74131f16fa62cafd2823d1d2d809b720d8414316 | |
| parent | 6d496e9569983a0d7a05be6661126d0702cf94f7 (diff) | |
Revert "drm/gem-dma: Use dma_buf from GEM object instance"
This reverts commit e8afa1557f4f963c9a511bd2c6074a941c308685.
The dma_buf field in struct drm_gem_object is not stable over the
object instance's lifetime. The field becomes NULL when user space
releases the final GEM handle on the buffer object. This resulted
in a NULL-pointer deref.
Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on
GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer:
Acquire internal references on GEM handles") only solved the problem
partially. They especially don't work for buffer objects without a DRM
framebuffer associated.
Hence, this revert to going back to using .import_attach->dmabuf.
v3:
- cc stable
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Zack Rusin <zack.rusin@broadcom.com>
Cc: <stable@vger.kernel.org> # v6.15+
Link: https://lore.kernel.org/r/20250715155934.150656-8-tzimmermann@suse.de
| -rw-r--r-- | drivers/gpu/drm/drm_gem_dma_helper.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_gem_dma_helper.c b/drivers/gpu/drm/drm_gem_dma_helper.c index b7f033d4352a..4f0320df858f 100644 --- a/drivers/gpu/drm/drm_gem_dma_helper.c +++ b/drivers/gpu/drm/drm_gem_dma_helper.c @@ -230,7 +230,7 @@ void drm_gem_dma_free(struct drm_gem_dma_object *dma_obj) if (drm_gem_is_imported(gem_obj)) { if (dma_obj->vaddr) - dma_buf_vunmap_unlocked(gem_obj->dma_buf, &map); + dma_buf_vunmap_unlocked(gem_obj->import_attach->dmabuf, &map); drm_prime_gem_destroy(gem_obj, dma_obj->sgt); } else if (dma_obj->vaddr) { if (dma_obj->map_noncoherent) |