Commit 6a15f3ff authored Sep 12, 2018 by Michel Dänzer Committed by Alex Deucher Sep 14, 2018

drm/amdgpu: Initialize fences array entries in amdgpu_sa_bo_next_hole



The entries were only initialized once in amdgpu_sa_bo_new. If a fence
wasn't signalled yet in the first amdgpu_sa_bo_next_hole call, but then
got signalled before a later amdgpu_sa_bo_next_hole call, it could
destroy the fence but leave its pointer in the array, resulting in
use-after-free in amdgpu_sa_bo_new.

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>

parent 520cbe0f

drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -226,6 +226,8 @@ static bool amdgpu_sa_bo_next_hole(struct amdgpu_sa_manager *sa_manager,
		for (i = 0; i < AMDGPU_SA_NUM_FENCE_LISTS; ++i) {
		struct amdgpu_sa_bo *sa_bo;

		fences[i] = NULL;

		if (list_empty(&sa_manager->flist[i]))
		continue;

		@@ -296,10 +298,8 @@ int amdgpu_sa_bo_new(struct amdgpu_sa_manager *sa_manager,

		spin_lock(&sa_manager->wq.lock);
		do {
		for (i = 0; i < AMDGPU_SA_NUM_FENCE_LISTS; ++i) {
		fences[i] = NULL;
		for (i = 0; i < AMDGPU_SA_NUM_FENCE_LISTS; ++i)
		tries[i] = 0;
		}

		do {
		amdgpu_sa_bo_try_free(sa_manager);

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