In the Linux kernel, the following vulnerability has been resolved:

scsi: ufs: exynos: Fix programming of HCI_UTRL_NEXUS_TYPE

On Google gs101, the number of UTP transfer request slots (nutrs) is 32,
and in this case the driver ends up programming the UTRL_NEXUS_TYPE
incorrectly as 0.

This is because the left hand side of the shift is 1, which is of type
int, i.e. 31 bits wide. Shifting by more than that width results in
undefined behaviour.

Fix this by switching to the BIT() macro, which applies correct type
casting as required. This ensures the correct value is written to
UTRL_NEXUS_TYPE (0xffffffff on gs101), and it also fixes a UBSAN shift
warning:

UBSAN: shift-out-of-bounds in drivers/ufs/host/ufs-exynos.c:1113:21
shift exponent 32 is too large for 32-bit type 'int'

For consistency, apply the same change to the nutmrs / UTMRL_NEXUS_TYPE
write.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 11 Sep 2025 17:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: exynos: Fix programming of HCI_UTRL_NEXUS_TYPE On Google gs101, the number of UTP transfer request slots (nutrs) is 32, and in this case the driver ends up programming the UTRL_NEXUS_TYPE incorrectly as 0. This is because the left hand side of the shift is 1, which is of type int, i.e. 31 bits wide. Shifting by more than that width results in undefined behaviour. Fix this by switching to the BIT() macro, which applies correct type casting as required. This ensures the correct value is written to UTRL_NEXUS_TYPE (0xffffffff on gs101), and it also fixes a UBSAN shift warning: UBSAN: shift-out-of-bounds in drivers/ufs/host/ufs-exynos.c:1113:21 shift exponent 32 is too large for 32-bit type 'int' For consistency, apply the same change to the nutmrs / UTMRL_NEXUS_TYPE write.
Title scsi: ufs: exynos: Fix programming of HCI_UTRL_NEXUS_TYPE
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-11T16:56:37.173Z

Reserved: 2025-04-16T07:20:57.131Z

Link: CVE-2025-39788

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-09-11T17:15:45.070

Modified: 2025-09-11T17:15:45.070

Link: CVE-2025-39788

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.