CVE-2026-64205i2c: i801: fix hardware state machine corruption in error path
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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.
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Aug 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 before 2ef69871b313aa0f02182795f5e0f5aa455f203c; from 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 before ef5a347532932f58748dad485c15039f5168c377; from 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 before bb5133a7d5f3fe5c387770e25f2e00e682ce11ed; from 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 before 00904687b9c5527d569d9a1ca72119823e735a61; from 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 before 10dd1a736d557e310a77117832874729a0175d57 | CNA record |
linux linux_kernel linux:linux_kernel | from 6.3 before 6.6.148; from 6.7 before 6.12.101; from 6.13 before 6.18.39; from 6.19 before 7.1.4 | NVD |
References
- https://git.kernel.org/stable/c/2ef69871b313aa0f02182795f5e0f5aa455f203cpatch
- https://git.kernel.org/stable/c/ef5a347532932f58748dad485c15039f5168c377patch
- https://git.kernel.org/stable/c/bb5133a7d5f3fe5c387770e25f2e00e682ce11edpatch
- https://git.kernel.org/stable/c/00904687b9c5527d569d9a1ca72119823e735a61patch
- https://git.kernel.org/stable/c/10dd1a736d557e310a77117832874729a0175d57patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.