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e07fc9e2da
When a guest performs an atomic/exclusive operation on memory lacking
the required attributes, user_mem_abort() injects a data abort and
returns early. However, it fails to release the reference to the
host page acquired via __kvm_faultin_pfn().
A malicious guest could repeatedly trigger this fault, leaking host
page references and eventually causing host memory exhaustion (OOM).
Fix this by consolidating the early error returns to a new out_put_page
label that correctly calls kvm_release_page_unused().
Fixes: 2937aeec9d ("KVM: arm64: Handle DABT caused by LS64* instructions on unsupported memory")
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Yuan Yao <yaoyuan@linux.alibaba.com>
Link: https://patch.msgid.link/20260304162222.836152-2-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>