wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 95% of all CVEs
observed exploitation
nono source reports it
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 products
Linux · Linux