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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-64205

i2c: i801: fix hardware state machine corruption in error path

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Status
Published
Published
Updated
Assigning organization
Linux

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 to < 2ef69871b313aa0f02182795f5e0f5aa455f203caffected
  • 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 to < ef5a347532932f58748dad485c15039f5168c377affected
  • 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 to < bb5133a7d5f3fe5c387770e25f2e00e682ce11edaffected
  • 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 to < 00904687b9c5527d569d9a1ca72119823e735a61affected
  • 1f760b87e54cf56a25ab68f8dc625e339f6e46d5 to < 10dd1a736d557e310a77117832874729a0175d57affected

Linux Linux

Default version status: affected

  • 6.3affected
  • 0 to < 6.3unaffected
  • 6.6.148 to ≤ 6.6.*unaffected
  • 6.12.101 to ≤ 6.12.*unaffected
  • 6.18.39 to ≤ 6.18.*unaffected
  • 7.1.4 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References