CVE-2025-39788: linux kernel vulnerability

What is known

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.

Business impact

Successful exploitation of CVE-2025-39788, a high vulnerability (CVSS 7.8) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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