CVE-2026-72142
kernel: i2c: imx: fix locked bus on SMBus block-read of 0 (atomic)
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · August 15, 2026
Updated · October 17, 2026
Description
A flaw was found in the i2c-imx driver of the Linux kernel. When an I2C slave device performs an SMBus block-read operation with a byte count of zero, the atomic (polling) path in the driver fails to properly release the I2C bus. This can cause the bus to become stuck, requiring a power cycle of the I2C controller to restore functionality. This issue leads to a denial of service for the affected system.
Statement
A low severity denial of service flaw was found in the i2c-imx driver of the Linux kernel, affecting the kernel and kernel-rt packages in Red Hat Enterprise Linux 9 and 10 and Red Hat In-Vehicle OS. When an SMBus block-read transaction returns a byte count of zero, or a count above I2C_SMBUS_BLOCK_MAX, the atomic (polling) path of the i2c-imx driver returns an error without issuing a NACK and STOP to terminate the transfer. Because the next receive cycle has already been armed, the I2C target keeps holding SDA, leaving the I2C bus locked until the i2c controller is power cycled, resulting in a denial of service limited to the affected I2C bus and controller. The flaw is local in nature (CVSS:3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, base score 5.5) and has no impact on confidentiality or integrity. Red Hat Enterprise Linux 6, 7, and 8 are not affected because the vulnerable code is not present in those releases. Given the low severity of this issue, the fix for the affected Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 10, and Red Hat In-Vehicle OS streams is deferred to a future update; the residual risk is a local denial of service confined to the I2C bus and controller of the affected system.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-772 · Missing Release of Resource after Effective Lifetime