CVE-2026-64570 PUBLISHED

wifi: mac80211: fix fils_discovery double free on alloc failure

Assigner: Linux
Reserved: 19.07.2026 Published: 05.08.2026 Updated: 05.08.2026

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

wifi: mac80211: fix fils_discovery double free on alloc failure

ieee80211_set_fils_discovery() calls kfree_rcu() on the old template before allocating the replacement. If the kzalloc() then fails, it returns -ENOMEM while link->u.ap.fils_discovery still points at the object already queued for freeing. A later update or AP teardown (ieee80211_stop_ap()) 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 ffff88800c065280 by task swapper/0/0 ... __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-96 of size 96

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().

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 3b1c256eb4aedfc71dd97d5951ccff824b41d628 to e2c55079155a953db669ca1986a985fa286bad95 (excl.)
  • affected from 3b1c256eb4aedfc71dd97d5951ccff824b41d628 to 5baaa1042f71dd4b8e418f2cdd516808702d229b (excl.)
  • affected from 3b1c256eb4aedfc71dd97d5951ccff824b41d628 to 1981fba71797ec95e6755fb882cad88899a2a84f (excl.)
  • affected from 3b1c256eb4aedfc71dd97d5951ccff824b41d628 to 286e52a799fa158bdbd77da1426c4d93f9a6e7ad (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.7 is affected
  • unaffected from 0 to 6.7 (excl.)
  • unaffected from 6.12.101 to 6.12.* (incl.)
  • unaffected from 6.18.42 to 6.18.* (incl.)
  • unaffected from 7.1.6 to 7.1.* (incl.)
  • unaffected from 7.2-rc4 to * (incl.)

References