i2c: core: fix debugfs UAF on adapter removal
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 1 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: i2c: core: fix debugfs UAF on adapter removal i2c_del_adapter() frees the adapter's debugfs directory before it unregisters the adapter device, but the new_device sysfs attribute stays writable until device_del(). A write racing with removal still reaches i2c_device_probe(), which passes the freed adap->debugfs to debugfs_create_dir() as the new client's parent: BUG: KASAN: slab-use-after-free in lookup_noperm_common+0x407/0x430 Read of size 4 at addr ffff88803ef87810 by task syz.0.61/6090 lookup_noperm_common+0x407/0x430 simple_start_creating+0x9c/0x110 debugfs_start_creating+0xdb/0x1a0 debugfs_create_dir+0x24/0x350 i2c_device_probe+0x814/0xbf0 It's technically possible to create a client after i2c_deregister_clients has run. That client will never be unregistered and make wait_for_completion hang. Close the window by removing the new_device attribute at the start of i2c_del_adapter(). device_remove_file() will drain any clients left.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.221, 6.1.188, 6.6.157
- Fix · CNA Linux (Linux) Fixed in 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
Not affected: 6 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-89983
- 2026-10-03 Alias added: GHSA-xr2v-8c9q-cqgw
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-25 Affected versions changed · Red Hat
- 2026-10-25 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 7
- https://git.kernel.org/stable/c/dc33a9762538b3250ed6b5644a4d44c748be33a6
- https://git.kernel.org/stable/c/1f1bcd4eca6caa3e4258d9a31925112539406eb6
- https://git.kernel.org/stable/c/f9094ace03e0a532cc6505d2e97b61ae738da4ed
- https://git.kernel.org/stable/c/643fb872aa04342d27dbef52b2b3cf3fe71b2c7b
- https://git.kernel.org/stable/c/112b3d48084c820bbccf41d9783fd122e3ac4cb0
- https://git.kernel.org/stable/c/552836be2d95c688eede6371f85532abe1a71232
- https://git.kernel.org/stable/c/b15b548d52b43ba8ac4652bc2c7244a8dd1e9622
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- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-89983 · CVE Program
- CVE-2026-89983 · NVD
- FIRST EPSS
- GHSA-xr2v-8c9q-cqgw · GitHub Advisory Database · CC BY 4.0
- CVE-2026-89983 · Red Hat security data · CC BY 4.0
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