CVE-2026-64205i2c: i801: fix hardware state machine corruption in error path
- 5.5MediumCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 98% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: i2c: i801: fix hardware state machine corruption in error path A severe livelock and subsequent Hung Task panic were observed in the i2c-i801 driver during concurrent Fuzzing. The crash is caused by an unconditional hardware register cleanup in the error handling path of i801_access(). When i801_check_pre() fails (e.g., returning -EBUSY because the SMBus controller is actively used by BIOS/ACPI), the kernel does not actually acquire the hardware ownership. However, the code jumps to the 'out' label and executes: iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv)); This forcefully clears the INUSE_STS lock and resets the hardware status flags without owning the controller. Doing so interrupts ongoing BIOS/ACPI transactions and totally corrupts the SMBus hardware state machine. Consequently, all subsequent i801_access() calls fail at the pre-check stage, triggering an endless stream of "SMBus is busy, can't use it!" error logs. Over a slow serial console, this printk flood monopolizes the CPU (Console Livelock), starving other processes trying to acquire the mmap_lock down_read semaphore, ultimately triggering the hung task watchdog. Fix this by moving the 'out' label below the hardware register cleanup. If i801_check_pre() fails, we safely bypass the iowrite8() and only release the software locks (pm_runtime and mutex), strictly adhering to the rule of not releasing resources that were never acquired.
Timeline
ID reserved
By Linux
- 1 day later
· 1 day later
Published
- 4 months later
· 4 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 98% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 – < 2ef69871b313aa0f02182795f5e0f5aa455f203c
- affected 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 – < ef5a347532932f58748dad485c15039f5168c377
- affected 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 – < bb5133a7d5f3fe5c387770e25f2e00e682ce11ed
- affected 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 – < 00904687b9c5527d569d9a1ca72119823e735a61
- affected 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 – < 10dd1a736d557e310a77117832874729a0175d57
- affected 6.3
- unaffected < 6.3
- unaffected 6.6.148 – ≤ 6.6.*
- unaffected 6.12.101 – ≤ 6.12.*
- unaffected 6.18.39 – ≤ 6.18.*
- unaffected 7.1.4 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References5
- https://git.kernel.org/stable/c/2ef69871b313aa0f02182795f5e0f5aa455f203c (opens in a new tab)
- https://git.kernel.org/stable/c/ef5a347532932f58748dad485c15039f5168c377 (opens in a new tab)
- https://git.kernel.org/stable/c/bb5133a7d5f3fe5c387770e25f2e00e682ce11ed (opens in a new tab)
- https://git.kernel.org/stable/c/00904687b9c5527d569d9a1ca72119823e735a61 (opens in a new tab)
- https://git.kernel.org/stable/c/10dd1a736d557e310a77117832874729a0175d57 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-46013 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64205)Record last updated .