CVE-2026-14367: zephyr Race Condition (CVSS 3.1)

Description

The I3C IBI subsystem in drivers/i3c/i3c_ibi_workq.c hands out statically-allocated work nodes through a free-list i3c_ibi_work_nodes_free implemented as a plain sys_slist_t, which provides no synchronization. The allocation helpers (i3c_ibi_work_enqueue, i3c_ibi_work_enqueue_target_irq, i3c_ibi_work_enqueue_hotjoin, i3c_ibi_work_enqueue_controller_request, i3c_ibi_work_enqueue_cb) called sys_slist_get() directly from ISR context, while the workqueue handler i3c_ibi_work_handler() returned nodes with sys_slist_append() from the workqueue thread, with no lock on either side. Because sys_slist_get() and sys_slist_append() are neither atomic nor interrupt-safe, an IBI interrupt that fires while the workqueue thread is mid-append (or a truly parallel access under CONFIG_SMP) races on the shared list. This corrupts the list linkage: a node may be handed to two consumers, a node may be lost, or the head/tail pointers may be left inconsistent so sys_slist_get() returns a stale or garbage pointer. In the double-hand-out case the subsequent memcpy(ibi_node, ibi_work, sizeof(*ibi_node)) overwrites a node still in flight; a garbage pointer turns the same memcpy into an out-of-bounds write. The race is driven by I3C bus traffic — IBIs, hot-joins, and controller-role requests originate from target devices on the bus, and I3C supports hot-joining devices. An attacker controlling an I3C peripheral on the board's chip-to-chip bus can generate high-frequency interrupts timed to collide with the free operation. Exploitation requires physical access to the bus and winning a narrow timing window; the most realistic impact is a crash or hang (denial of service), with memory corruption possible but hard to control. The fix wraps all free-list sys_slist_get()/sys_slist_append() operations in the new ibi_work_alloc()/ibi_work_free() helpers, each guarded by a k_spinlock (ibi_work_lock), closing the race across ISR and thread contexts.

Metrics

CVSS 3.1

3.1/10

CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

EPSS Probability

0.10%

1.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
zephyrproject	zephyr	>= 3.2.0, < 4.4.2

References

Timeline

Published: Aug 31, 2026
Last Modified: Sep 1, 2026
Status: Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-14367?

The I3C IBI subsystem in drivers/i3c/i3c_ibi_workq.c hands out statically-allocated work nodes through a free-list i3c_ibi_work_nodes_free implemented as a plain sys_slist_t, which provides no synchronization. The allocation helpers (i3c_ibi_work_enqueue, i3c_ibi_work_enqueue_target_irq, i3c_ibi_work_enqueue_hotjoin, i3c_ibi_work_enqueue_controller_request, i3c_ibi_work_enqueue_cb) called sys_slist_get() directly from ISR context, while the workqueue handler i3c_ibi_work_handler() returned nodes with sys_slist_append() from the workqueue thread, with no lock on either side. Because sys_slist_get() and sys_slist_append() are neither atomic nor interrupt-safe, an IBI interrupt that fires while the workqueue thread is mid-append (or a truly parallel access under CONFIG_SMP) races on the shared list. This corrupts the list linkage: a node may be handed to two consumers, a node may be lost, or the head/tail pointers may be left inconsistent so sys_slist_get() returns a stale or garbage pointer. In the double-hand-out case the subsequent memcpy(ibi_node, ibi_work, sizeof(*ibi_node)) overwrites a node still in flight; a garbage pointer turns the same memcpy into an out-of-bounds write. The race is driven by I3C bus traffic — IBIs, hot-joins, and controller-role requests originate from target devices on the bus, and I3C supports hot-joining devices. An attacker controlling an I3C peripheral on the board's chip-to-chip bus can generate high-frequency interrupts timed to collide with the free operation. Exploitation requires physical access to the bus and winning a narrow timing window; the most realistic impact is a crash or hang (denial of service), with memory corruption possible but hard to control. The fix wraps all free-list sys_slist_get()/sys_slist_append() operations in the new ibi_work_alloc()/ibi_work_free() helpers, each guarded by a k_spinlock (ibi_work_lock), closing the race across ISR and thread contexts.

How severe is CVE-2026-14367?

CVE-2026-14367 has a CVSS score of 3.1/10 (LOW severity). The EPSS model estimates a 0.10% probability of exploitation in the next 30 days.

How do I fix CVE-2026-14367?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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