From: xinhui pan xinhui.pan@amd.com

stable inclusion from stable-v4.19.193 commit a849e218556f932576c0fb1c5a88714b61709a17 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9BGUB CVE: CVE-2021-47142

Reference: https://git.kernel.org/stable/c/a849e218556f932576c0fb1c5a88714b61709a17

--------------------------------

[ Upstream commit 1e5c37385097c35911b0f8a0c67ffd10ee1af9a2 ]

looks like we forget to set ttm->sg to NULL. Hit panic below

[ 1235.844104] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b7b4b: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 1235.989074] Call Trace: [ 1235.991751] sg_free_table+0x17/0x20 [ 1235.995667] amdgpu_ttm_backend_unbind.cold+0x4d/0xf7 [amdgpu] [ 1236.002288] amdgpu_ttm_backend_destroy+0x29/0x130 [amdgpu] [ 1236.008464] ttm_tt_destroy+0x1e/0x30 [ttm] [ 1236.013066] ttm_bo_cleanup_memtype_use+0x51/0xa0 [ttm] [ 1236.018783] ttm_bo_release+0x262/0xa50 [ttm] [ 1236.023547] ttm_bo_put+0x82/0xd0 [ttm] [ 1236.027766] amdgpu_bo_unref+0x26/0x50 [amdgpu] [ 1236.032809] amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu+0x7aa/0xd90 [amdgpu] [ 1236.040400] kfd_ioctl_alloc_memory_of_gpu+0xe2/0x330 [amdgpu] [ 1236.046912] kfd_ioctl+0x463/0x690 [amdgpu]

Signed-off-by: xinhui pan xinhui.pan@amd.com Reviewed-by: Christian König christian.koenig@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: GUO Zihua guozihua@huawei.com --- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index fcf421263fd9..47728a7bd837 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -1276,6 +1276,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm) if (gtt && gtt->userptr) { amdgpu_ttm_tt_set_user_pages(ttm, NULL); kfree(ttm->sg); + ttm->sg = NULL; ttm->page_flags &= ~TTM_PAGE_FLAG_SG; return; }