This is a note to let you know that I've just added the patch titled drm/ttm: stop calling tt_swapin in vm_access to the 5.14-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-stop-calling-tt_swapin-in-vm_access.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 13cba41d191cd26c27350bb922aaf7d074d1ae74 Author: Matthew Auld <matthew.auld@xxxxxxxxx> Date: Mon Sep 27 12:41:02 2021 +0100 drm/ttm: stop calling tt_swapin in vm_access [ Upstream commit f5d28856b89baab4232a9f841e565763fcebcdf9 ] In commit: commit 09ac4fcb3f255e9225967c75f5893325c116cdbe Author: Felix Kuehling <Felix.Kuehling@xxxxxxx> Date: Thu Jul 13 17:01:16 2017 -0400 drm/ttm: Implement vm_operations_struct.access v2 we added the vm_access hook, where we also directly call tt_swapin for some reason. If something is swapped-out then the ttm_tt must also be unpopulated, and since access_kmap should also call tt_populate, if needed, then swapping-in will already be handled there. If anything, calling tt_swapin directly here would likely always fail since the tt->pages won't yet be populated, or worse since the tt->pages array is never actually cleared in unpopulate this might lead to a nasty uaf. Fixes: 09ac4fcb3f25 ("drm/ttm: Implement vm_operations_struct.access v2") Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx> Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx> Cc: Christian König <christian.koenig@xxxxxxx> Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx> Reviewed-by: Christian König <christian.koenig@xxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210927114114.152310-1-matthew.auld@xxxxxxxxx Signed-off-by: Christian König <christian.koenig@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index f56be5bc0861e..5b9b7fd01a692 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -519,11 +519,6 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, switch (bo->resource->mem_type) { case TTM_PL_SYSTEM: - if (unlikely(bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) { - ret = ttm_tt_swapin(bo->ttm); - if (unlikely(ret != 0)) - return ret; - } fallthrough; case TTM_PL_TT: ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);