CVE-2026-64568wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure ieee80211_set_unsol_bcast_probe_resp() calls kfree_rcu() on the old template before allocating the replacement. If the kzalloc() then fails, it returns -ENOMEM while link->u.ap.unsol_bcast_probe_resp still points at the object already queued for freeing. A later update or AP teardown re-queues that same rcu_head; the second free is caught by KASAN when the RCU sheaf is processed in softirq: BUG: KASAN: double-free in rcu_free_sheaf (mm/slub.c:5850) Free of addr ffff88800d06f300 by task exploit/145 ... __rcu_free_sheaf_prepare (mm/slub.c:2634 mm/slub.c:2940) rcu_free_sheaf (mm/slub.c:5850) rcu_core (kernel/rcu/tree.c:2617 kernel/rcu/tree.c:2869) handle_softirqs (kernel/softirq.c:622) The buggy address belongs to the cache kmalloc-128 of size 128 Queue the old object for kfree_rcu() only after the new one is published, matching ieee80211_set_probe_resp() and ieee80211_set_s1g_short_beacon().

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/ca27a81cd77b698e5eb586a011bee6800c7ee4bd
• https://git.kernel.org/stable/c/d62b55b7c7dc62887d7fd5648fb38f0bfaef53ae
• https://git.kernel.org/stable/c/0ace76e410d7f7d813b605825a3e593a79c3958f
• https://git.kernel.org/stable/c/1d067abcd37062426c59ec73dbc4e87a63f33fea