amdxdna_umap_release() calls the blocking mmu_interval_notifier_remove()
before removing the object from abo->mem.umap_list. If
aie2_populate_range() runs concurrently, it may obtain a reference to an
amdxdna_umap that is being released, leading to a potential use-after-free.
Use kref_get_unless_zero() in aie2_populate_range() when acquiring a
reference. If the reference count has already dropped to zero, release
is in progress and the entry is skipped.
Fixes: e486147c91 ("accel/amdxdna: Add BO import and export")
Reviewed-by: Max Zhen <max.zhen@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260706221228.434099-1-lizhi.hou@amd.com
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