Patch "drm/ttm: Always and only destroy bo->ttm_resv in ttm_bo_release_list" has been added to the 4.14-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/ttm: Always and only destroy bo->ttm_resv in ttm_bo_release_list

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-ttm-always-and-only-destroy-bo-ttm_resv-in-ttm_bo_release_list.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From e1fc12c5d9ad06a2a74e97a91f1b0c5f4c723b50 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michel=20D=C3=A4nzer?= <michel.daenzer@amd.com>
Date: Fri, 3 Nov 2017 16:00:35 +0100
Subject: drm/ttm: Always and only destroy bo->ttm_resv in ttm_bo_release_list
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From: Michel Dänzer <michel.daenzer@amd.com>

commit e1fc12c5d9ad06a2a74e97a91f1b0c5f4c723b50 upstream.

Fixes a use-after-free due to a race condition in
ttm_bo_cleanup_refs_and_unlock, which allows one task to reserve a BO
and destroy its ttm_resv while another task is waiting for it to signal
in reservation_object_wait_timeout_rcu.

v2:
* Always initialize bo->ttm_resv in ttm_bo_init_reserved
 (Christian König)

Fixes: 0d2bd2ae045d "drm/ttm: fix memory leak while individualizing BOs"
Reviewed-by: Chunming Zhou <david1.zhou@amd.com> # v1
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/ttm/ttm_bo.c |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -150,8 +150,7 @@ static void ttm_bo_release_list(struct k
 	ttm_tt_destroy(bo->ttm);
 	atomic_dec(&bo->glob->bo_count);
 	dma_fence_put(bo->moving);
-	if (bo->resv == &bo->ttm_resv)
-		reservation_object_fini(&bo->ttm_resv);
+	reservation_object_fini(&bo->ttm_resv);
 	mutex_destroy(&bo->wu_mutex);
 	if (bo->destroy)
 		bo->destroy(bo);
@@ -402,14 +401,11 @@ static int ttm_bo_individualize_resv(str
 	if (bo->resv == &bo->ttm_resv)
 		return 0;
 
-	reservation_object_init(&bo->ttm_resv);
 	BUG_ON(!reservation_object_trylock(&bo->ttm_resv));
 
 	r = reservation_object_copy_fences(&bo->ttm_resv, bo->resv);
-	if (r) {
+	if (r)
 		reservation_object_unlock(&bo->ttm_resv);
-		reservation_object_fini(&bo->ttm_resv);
-	}
 
 	return r;
 }
@@ -459,6 +455,7 @@ static void ttm_bo_cleanup_refs_or_queue
 			spin_unlock(&glob->lru_lock);
 			if (bo->resv != &bo->ttm_resv)
 				reservation_object_unlock(&bo->ttm_resv);
+
 			ttm_bo_cleanup_memtype_use(bo);
 			return;
 		}
@@ -1205,8 +1202,8 @@ int ttm_bo_init_reserved(struct ttm_bo_d
 		lockdep_assert_held(&bo->resv->lock.base);
 	} else {
 		bo->resv = &bo->ttm_resv;
-		reservation_object_init(&bo->ttm_resv);
 	}
+	reservation_object_init(&bo->ttm_resv);
 	atomic_inc(&bo->glob->bo_count);
 	drm_vma_node_reset(&bo->vma_node);
 	bo->priority = 0;


Patches currently in stable-queue which might be from michel.daenzer@amd.com are

queue-4.14/drm-amdgpu-reserve-root-pd-while-releasing-it.patch
queue-4.14/drm-amdgpu-set-adev-vcn.irq.num_types-for-vcn.patch
queue-4.14/drm-amdgpu-fix-error-handling-in-amdgpu_bo_do_create.patch
queue-4.14/drm-ttm-always-and-only-destroy-bo-ttm_resv-in-ttm_bo_release_list.patch
queue-4.14/revert-drm-radeon-dont-switch-vt-on-suspend.patch
queue-4.14/drm-amdgpu-move-uvd-vce-and-vcn-structure-out-from-union.patch