i915: don't use a vma that didn't match the context VM

In eb_lookup_vma(), the code checks that the context vm matches before
incrementing the i915 vma usage count, but for the non-matching case it
didn't clear the non-matching vma pointer, so it would then mistakenly
be returned, causing potential UaF and refcount issues.

Reported-by: Yassine Mounir <sosohero200@gmail.com>
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds
2026-04-05 12:42:25 -07:00
parent eb3765aa71
commit 5401b9adeb

View File

@@ -898,6 +898,8 @@ static struct i915_vma *eb_lookup_vma(struct i915_execbuffer *eb, u32 handle)
vma = radix_tree_lookup(&eb->gem_context->handles_vma, handle);
if (likely(vma && vma->vm == vm))
vma = i915_vma_tryget(vma);
else
vma = NULL;
rcu_read_unlock();
if (likely(vma))
return vma;