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author | 2022-06-20 14:36:59 +0200 | |
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committer | 2022-07-12 18:16:40 -0400 | |
commit | 48da0f67c53eecd2594c302be6c8a665b7740eaf (patch) | |
tree | 2bdd18e9a663ff589fde610b796abdf820c39a80 /drivers/gpu | |
parent | drm/i915/guc: ADL-N should use the same GuC FW as ADL-S (diff) | |
download | linux-48da0f67c53eecd2594c302be6c8a665b7740eaf.tar.gz linux-48da0f67c53eecd2594c302be6c8a665b7740eaf.tar.bz2 linux-48da0f67c53eecd2594c302be6c8a665b7740eaf.zip |
drm/i915: Fix vm use-after-free in vma destruction
In vma destruction, the following race may occur:
Thread 1: Thread 2:
i915_vma_destroy();
...
list_del_init(vma->vm_link);
...
mutex_unlock(vma->vm->mutex);
__i915_vm_release();
release_references();
And in release_reference() we dereference vma->vm to get to the
vm gt pointer, leading to a use-after free.
However, __i915_vm_release() grabs the vm->mutex so the vm won't be
destroyed before vma->vm->mutex is released, so extract the gt pointer
under the vm->mutex to avoid the vma->vm dereference in
release_references().
v2: Fix a typo in the commit message (Andi Shyti)
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5944
Fixes: e1a7ab4fca0c ("drm/i915: Remove the vm open count")
Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Nirmoy Das <nirmoy.das@intel.con>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220620123659.381772-1-thomas.hellstrom@linux.intel.com
(cherry picked from commit 1926a6b75954fc1a8b44d10bd0c67db957b78cf7)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r-- | drivers/gpu/drm/i915/i915_vma.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index 0bffb70b3c5f..04d12f278f57 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -1637,10 +1637,10 @@ static void force_unbind(struct i915_vma *vma) GEM_BUG_ON(drm_mm_node_allocated(&vma->node)); } -static void release_references(struct i915_vma *vma, bool vm_ddestroy) +static void release_references(struct i915_vma *vma, struct intel_gt *gt, + bool vm_ddestroy) { struct drm_i915_gem_object *obj = vma->obj; - struct intel_gt *gt = vma->vm->gt; GEM_BUG_ON(i915_vma_is_active(vma)); @@ -1695,11 +1695,12 @@ void i915_vma_destroy_locked(struct i915_vma *vma) force_unbind(vma); list_del_init(&vma->vm_link); - release_references(vma, false); + release_references(vma, vma->vm->gt, false); } void i915_vma_destroy(struct i915_vma *vma) { + struct intel_gt *gt; bool vm_ddestroy; mutex_lock(&vma->vm->mutex); @@ -1707,8 +1708,11 @@ void i915_vma_destroy(struct i915_vma *vma) list_del_init(&vma->vm_link); vm_ddestroy = vma->vm_ddestroy; vma->vm_ddestroy = false; + + /* vma->vm may be freed when releasing vma->vm->mutex. */ + gt = vma->vm->gt; mutex_unlock(&vma->vm->mutex); - release_references(vma, vm_ddestroy); + release_references(vma, gt, vm_ddestroy); } void i915_vma_parked(struct intel_gt *gt) |