CVE-2026-97599 ieee802154: hwsim: serialize pib updates to fix double-free
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-97599?
CVE-2026-97599 is a vulnerability in Linux, published on 25 Sep 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ieee802154: hwsim: serialize pib updates to fix double-free
hwsim_update_pib() does an unserialized read-swap-free of phy->pib:
pib_old = rtnl_dereference(phy->pib); ... rcu_assign_pointer(phy->pib, pib); kfree_rcu(pib_old, rcu);
It assumes the RTNL is held, but ->set_channel is not always called under it: the mac802154 scan worker changes channels via drv_set_channel() without the RTNL. Such an update can race an RTNL-held one on the same phy; both read the same pib_old and both kfree_rcu() it, double-freeing the object. With SLUB percpu sheaves batching kfree_rcu(), this surfaces as a KASAN invalid-free in rcu_free_sheaf().
struct hwsim_phy has no lock for pib. Add one and make the swap atomic with rcu_replace_pointer() under it, dropping the misleading rtnl_dereference().
Which versions are affected by CVE-2026-97599?
How do I fix CVE-2026-97599?
Upgrade to a fixed version.
Is CVE-2026-97599 being exploited?
There is no known exploitation of CVE-2026-97599 in the wild and no public exploit code.
Sources
Also known as AZL-104658, BELL-CVE-2026-97599, DEBIAN-CVE-2026-97599, GHSA-r8g8-vw6g-m8xh, UBUNTU-CVE-2026-97599.