CVE-2026-72141: i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)
In the Linux kernel, the following vulnerability has been resolved:
i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)
SMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the interrupt-driven block-read state machine rejects it as -EPROTO. Worse, it returns without a NACK+STOP: the next receive cycle has already started, so the target keeps holding SDA and the bus stays stuck until a power cycle of this i2c controller.
Accept count=0: NACK the in-flight dummy byte (TXAK) and set msg->len to 2 so i2cimxisrreadcontinue() emits STOP via its normal last-byte path. The dummy byte is discarded; block-read callers only consume buf[0..count-1].
Reading I2DR has likewise already armed the next byte on the count > I2CSMBUSBLOCKMAX error path, so NACK it (TXAK) before aborting with -EPROTO; otherwise the failing transfer's STOP cannot complete and the bus stays held.
The atomic path regressed earlier (v3.16) and is fixed separately; this patch covers only the v6.13 state-machine rework.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72141?
CVE-2026-72141 carries a risk rating of 21.
How do I fix CVE-2026-72141?
To mitigate CVE-2026-72141, ensure your Linux kernel is updated to the patched version.
What impact does CVE-2026-72141 have on systems?
CVE-2026-72141 can cause a locked SMBus state during block-read operations when the byte count is set to 0.
What systems are affected by CVE-2026-72141?
Devices utilizing the affected Linux kernel versions with i2c: imx are susceptible to CVE-2026-72141.
When was CVE-2026-72141 published?
CVE-2026-72141 was published on August 15, 2026.