debugobjects: Plug race against a concurrent OOM disable
Summary
| CVE | CVE-2026-68090 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-10 12:17:21 UTC |
| Updated | 2026-08-10 12:17:21 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved:
debugobjects: Plug race against a concurrent OOM disable
syzbot reported a puzzling splat:
WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20
stub_timer() is installed as timer callback function in
hrtimer_fixup_assert_init(), which is invoked when
debug_object_assert_init() can't find a shadow object. In that case debug
objects emits a warning about it before invoking the fixup.
Though the provided console log lacks this warning and instead has the
following a few seconds before the splat:
ODEBUG: Out of memory. ODEBUG disabled
So the object was looked up in debug_object_assert_init() and the lookup
failed due a concurrent out of memory situation which disabled debug
objects and freed the shadow objects:
debug_object_assert_init()
if (!debug_objects_enabled)
return; obj = alloc();
if (!obj) {
// Out of memory
debug_objects_enabled = false;
free_objects();
obj = lookup_or_alloc();
// The lookup failed because the other side
// removed the objects, so this returns
// an error code as the object in question
// is not statically initialized
if (!IS_ERR_OR_NULL(obj))
return;
if (!obj) {
debug_oom();
return;
}
print(...)
if (!debug_objects_enabled)
return;
fixup(...)
The debug object splat is skipped because debug_objects_enabled is false,
but the fixup callback is invoked unconditionally, which makes the timer
disfunctional.
This is only a problem in debug_object_assert_init() and
debug_object_activate() as both have to handle statically initialized
objects and therefore must handle the error pointer return case
gracefully. All other places only handle the found/not found case and the
NULL pointer return is a signal for OOM. Otherwise they get a valid shadow
object.
Plug the hole by checking whether debug objects are still enabled before
invoking the print and fixup function in those two places. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 2d5e320b7ab9b25229ac4331541964a58b5e1d29 git |
Not specified |
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 203a965bf2ab43130778d8214fb0c3c8c2d19cdf git |
Not specified |
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 23da32e88627e63e0864f59f4c63a2dc0ab851a3 git |
Not specified |
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 d663fbf28b2eebe665bb9cf828d7d528e5a8707e git |
Not specified |
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 e2e255d07723c330dded8e576ce28a8d23a692ce git |
Not specified |
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 c00164c9e7fa6145886ad666806cb5347895de5c git |
Not specified |
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 1f4f02b336c3be125c8fcf87df73db2e0e028b8b git |
Not specified |
| CNA |
Linux |
Linux |
affected b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 b81dde13cc163450dcb402dcc915ef13ba241e01 git |
Not specified |
| CNA |
Linux |
Linux |
affected 3.3 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 3.3 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.10.261 5.10.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.15.212 5.15.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.178 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.145 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.96 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.39 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.1.4 7.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/2d5e320b7ab9b25229ac4331541964a58b5e1d29 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/d663fbf28b2eebe665bb9cf828d7d528e5a8707e |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c00164c9e7fa6145886ad666806cb5347895de5c |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/b81dde13cc163450dcb402dcc915ef13ba241e01 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/23da32e88627e63e0864f59f4c63a2dc0ab851a3 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/203a965bf2ab43130778d8214fb0c3c8c2d19cdf |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/e2e255d07723c330dded8e576ce28a8d23a692ce |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/1f4f02b336c3be125c8fcf87df73db2e0e028b8b |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.