CVE-2026-53212

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nft_tunnel: fix use-after-free on object destroy

nft_tunnel_obj_destroy() calls metadata_dst_free() which directly

kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets

that took a reference via dst_hold() in nft_tunnel_obj_eval() and

are still queued (e.g. in a netem qdisc) are left with a dangling

pointer. When these packets are eventually dequeued, dst_release()

operates on freed memory.

Replace metadata_dst_free() with dst_release() so the metadata_dst

is freed only after all references are dropped. The dst subsystem

already handles metadata_dst cleanup in dst_destroy() when

DST_METADATA is set.