CVE-2026-68409 is a vulnerability in Linux Kernel
Published on August 10, 2026
wifi: mac80211: defer link RX stats percpu free to RCU
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: defer link RX stats percpu free to RCU
sta_remove_link() frees a removed MLO link's RX stats percpu buffer right
away, but defers only the link container to RCU:
sta_info_free_link(&alloc->info);
kfree_rcu(alloc, rcu_head);
The RX fast path reads link_sta under rcu_read_lock and writes the percpu
stats. A reader that resolved link_sta before the removal keeps the
pointer. The container stays alive from the kfree_rcu, so the read still
works. But the percpu block it points to is already freed. This needs
uses_rss. That is when pcpu_rx_stats exists.
The full STA teardown frees the deflink stats only after
synchronize_net(). The link removal path had no such barrier. The race is
hard to win in practice, but the free should still wait for RCU.
Free the link together with its data from a single RCU callback, so the
percpu block is reclaimed only after readers drain.
Products Associated with CVE-2026-68409
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Affected Versions
Linux:- Version c71420db653aba30a234d1e4cf86dde376e604fa and below 2aa1789880fa5e41049b0f6a74a4fc2fa1997610 is affected.
- Version c71420db653aba30a234d1e4cf86dde376e604fa and below a03fceae0c65b31ce31840dac5e26684ceecb65b is affected.
- Version c71420db653aba30a234d1e4cf86dde376e604fa and below aa2eb62525188269cdd402a583b9a8ed94657ff0 is affected.
- Version 6.0 is affected.
- Before 6.0 is unaffected.
- Version 6.18.42, <= 6.18.* is unaffected.
- Version 7.1.6, <= 7.1.* is unaffected.
- Version 7.2-rc4, <= * is unaffected.