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| author | Lv Yunlong <lyl2019@mail.ustc.edu.cn> | 2021-04-26 15:43:40 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2021-05-12 20:52:40 +0300 |
| commit | ea995218dddba171fecd05496c69617c5ef3c5b8 (patch) | |
| tree | dc473a167df0912075be181dde23f0fe22cbcca8 /drivers/gpu/drm/i915/gt | |
| parent | 04d019961fd15de92874575536310243a0d4c5c5 (diff) | |
| download | linux-ea995218dddba171fecd05496c69617c5ef3c5b8.tar.xz | |
drm/i915/gt: Fix a double free in gen8_preallocate_top_level_pdp
Our code analyzer reported a double free bug.
In gen8_preallocate_top_level_pdp, pde and pde->pt.base are allocated
via alloc_pd(vm) with one reference. If pin_pt_dma() failed, pde->pt.base
is freed by i915_gem_object_put() with a reference dropped. Then free_pd
calls free_px() defined in intel_ppgtt.c, which calls i915_gem_object_put()
to put pde->pt.base again.
As pde->pt.base is protected by refcount, so the second put will not free
pde->pt.base actually. But, maybe it is better to remove the first put?
Fixes: 82adf901138cc ("drm/i915/gt: Shrink i915_page_directory's slab bucket")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210426124340.4238-1-lyl2019@mail.ustc.edu.cn
(cherry picked from commit ac69496fe65cca0611d5917b7d232730ff605bc7)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/gt')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/gen8_ppgtt.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c index 176c19633412..74bf6fc8461f 100644 --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c @@ -641,7 +641,6 @@ static int gen8_preallocate_top_level_pdp(struct i915_ppgtt *ppgtt) err = pin_pt_dma(vm, pde->pt.base); if (err) { - i915_gem_object_put(pde->pt.base); free_pd(vm, pde); return err; } |