Zephyr's dynamic kernel-object tracking (kernel/userspace/userspace.c, formerly kernel/userspace.c) maintains a doubly-linked list (obj_list) of dynamically allocated kernel objects. Iteration over this list in k_object_wordlist_foreach() was performed under lists_lock using the SAFE iterator (which caches the next node), but list removal and freeing of nodes was performed under different, disjoint spinlocks: objfree_lock in k_object_free() and obj_lock in unref_check(). On an SMP system, while one CPU iterated obj_list under lists_lock, another CPU could unlink and k_free() the dyn_obj node that the iterator had cached as its next pointer, causing the iterator to dereference freed kernel memory (use-after-free / dangling list traversal). All of the racing operations are reachable from unprivileged user-mode threads via system calls: k_object_alloc/k_object_alloc_size and k_object_release drive removals through unref_check() (under obj_lock), while k_thread_abort and thread creation drive the iteration through k_thread_perms_all_clear()/k_thread_perms_inherit() (under lists_lock). A deprivileged user thread on a CONFIG_SMP + CONFIG_USERSPACE build can therefore corrupt the kernel's object-tracking structures across the userspace security boundary, yielding kernel memory corruption (potential privilege escalation) or a kernel crash (denial of service). The fix removes objfree_lock and serializes every obj_list modification under lists_lock, including holding it across find+remove in k_object_free() and around unref_check() in k_thread_perms_clear(). Affects CONFIG_SMP+CONFIG_USERSPACE+CONFIG_DYNAMIC_OBJECTS configurations; the defect dates to the 2019 spinlockification (commit 8a3d57b6cc6, first released in v1.14.0) and shipped through v4.4.0.
References
| Link | Resource |
|---|---|
| https://github.com/zephyrproject-rtos/zephyr/commit/fdc42fa256b8c2a7b27790f032d5385f8058c4a9 | Patch |
| https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-9x5j-h3rh-x579 | Exploit Patch Vendor Advisory |
| https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-9x5j-h3rh-x579 | Exploit Patch Vendor Advisory |
Configurations
History
16 Jul 2026, 20:19
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:* | |
| First Time |
Zephyrproject zephyr
Zephyrproject |
|
| References | () https://github.com/zephyrproject-rtos/zephyr/commit/fdc42fa256b8c2a7b27790f032d5385f8058c4a9 - Patch | |
| References | () https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-9x5j-h3rh-x579 - Exploit, Patch, Vendor Advisory |
13 Jul 2026, 17:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-9x5j-h3rh-x579 - |
12 Jul 2026, 17:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-12 17:16
Updated : 2026-07-16 20:19
NVD link : CVE-2026-10667
Mitre link : CVE-2026-10667
CVE.ORG link : CVE-2026-10667
JSON object : View
Products Affected
zephyrproject
- zephyr
CWE
CWE-416
Use After Free
