Am 14.06.23 um 18:15 schrieb Jeffrey Hugo:

From: Pranjal Ramajor Asha Kanojiya quic_pkanojiy@quicinc.com

smatch warning: drivers/accel/qaic/qaic_data.c:620 qaic_free_object() error: dereferencing freed memory 'obj->import_attach'

obj->import_attach is detached and freed using dma_buf_detach(). But used after free to decrease the dmabuf ref count using dma_buf_put().

drm_prime_gem_destroy() handles this issue and performs the proper clean up instead of open coding it in the driver.

Fixes: ff13be830333 ("accel/qaic: Add datapath") Reported-by: Sukrut Bellary sukrut.bellary@linux.com Closes: https://lore.kernel.org/all/20230610021200.377452-1-sukrut.bellary@linux.com... Suggested-by: Christian König christian.koenig@amd.com Signed-off-by: Pranjal Ramajor Asha Kanojiya quic_pkanojiy@quicinc.com Reviewed-by: Carl Vanderlip quic_carlv@quicinc.com Reviewed-by: Jeffrey Hugo quic_jhugo@quicinc.com Signed-off-by: Jeffrey Hugo quic_jhugo@quicinc.com

Reviewed-by: Christian König christian.koenig@amd.com

---

drivers/accel/qaic/qaic_data.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/accel/qaic/qaic_data.c b/drivers/accel/qaic/qaic_data.c index e42c1f9ffff8..e9a1cb779b30 100644 --- a/drivers/accel/qaic/qaic_data.c +++ b/drivers/accel/qaic/qaic_data.c @@ -23,6 +23,7 @@ #include <linux/wait.h> #include <drm/drm_file.h> #include <drm/drm_gem.h> +#include <drm/drm_prime.h> #include <drm/drm_print.h> #include <uapi/drm/qaic_accel.h> @@ -616,8 +617,7 @@ static void qaic_free_object(struct drm_gem_object *obj) if (obj->import_attach) { /* DMABUF/PRIME Path */

• dma_buf_detach(obj->import_attach->dmabuf, obj->import_attach);
  

• dma_buf_put(obj->import_attach->dmabuf);
  

• drm_prime_gem_destroy(obj, NULL);
  

  } else { /* Private buffer allocation path */ qaic_free_sgt(bo->sgt);