This is a note to let you know that I've just added the patch titled drm/i915/selftests: Fix i915_address_space refcnt leak to the 5.6-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-i915-selftests-fix-i915_address_space-refcnt-lea.patch and it can be found in the queue-5.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit a3f9504e103d40f41c69549c4e286af8fef25254 Author: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Date: Mon Apr 20 13:41:54 2020 +0800 drm/i915/selftests: Fix i915_address_space refcnt leak commit 5d5e100a20348c336e56df604b353b978f8adbb9 upstream. igt_ppgtt_pin_update() invokes i915_gem_context_get_vm_rcu(), which returns a reference of the i915_address_space object to "vm" with increased refcount. When igt_ppgtt_pin_update() returns, "vm" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in two exception handling paths of igt_ppgtt_pin_update(). When i915_gem_object_create_internal() returns IS_ERR, the refcnt increased by i915_gem_context_get_vm_rcu() is not decreased, causing a refcnt leak. Fix this issue by jumping to "out_vm" label when i915_gem_object_create_internal() returns IS_ERR. Fixes: a4e7ccdac38e ("drm/i915: Move context management under GEM") Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx> Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/1587361342-83494-1-git-send-email-xiyuyang19@xxxxxxxxxxxx (cherry picked from commit e07c7606a00c4361bad72ff4e72ed0dfbefa23b0) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c index 9311250d7d6f9..7a7763be6b2e3 100644 --- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c +++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c @@ -1578,8 +1578,10 @@ static int igt_ppgtt_pin_update(void *arg) unsigned int page_size = BIT(first); obj = i915_gem_object_create_internal(dev_priv, page_size); - if (IS_ERR(obj)) - return PTR_ERR(obj); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto out_vm; + } vma = i915_vma_instance(obj, vm, NULL); if (IS_ERR(vma)) { @@ -1632,8 +1634,10 @@ static int igt_ppgtt_pin_update(void *arg) } obj = i915_gem_object_create_internal(dev_priv, PAGE_SIZE); - if (IS_ERR(obj)) - return PTR_ERR(obj); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto out_vm; + } vma = i915_vma_instance(obj, vm, NULL); if (IS_ERR(vma)) {