CVE-2026-72141

Technical Description

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 i2c_imx_isr_read_continue() 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 > I2C_SMBUS_BLOCK_MAX 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-mac

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References