Bug 2541242 (CVE-2026-97599)

Summary: CVE-2026-97599 kernel: ieee802154: hwsim: serialize pib updates to fix double-free
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's IEEE 802.15.4 hardware simulator driver. A lack of proper locking allows concurrent channel updates to race against each other when modifying simulated device configuration parameters. A local user could exploit this flaw to cause a double-free memory corruption condition, leading to a Denial of Service (DoS) through a system crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-25 11:09:28 UTC 
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().
Comment 1 gkamathe 2026-09-29 11:41:48 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97599.mbox