From: Xiyu Yang xiyuyang19@fudan.edu.cn
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@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Link: https://patchwork.freedesktop.org/patch/msgid/1587361342-83494-1-git-send-em... (cherry picked from commit e07c7606a00c4361bad72ff4e72ed0dfbefa23b0) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i915/gem/selftests/huge_pages.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
--- 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 *ar 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 *ar }
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)) {