CVE-2025-71200

/// Technical description

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

mmc: sdhci-of-dwcmshc: Prevent illegal clock reduction in HS200/HS400 mode

When operating in HS200 or HS400 timing modes, reducing the clock frequency

below 52MHz will lead to link broken as the Rockchip DWC MSHC controller

requires maintaining a minimum clock of 52MHz in these modes.

Add a check to prevent illegal clock reduction through debugfs:

root@debian:/# echo 50000000 > /sys/kernel/debug/mmc0/clock

root@debian:/# [ 30.090146] mmc0: running CQE recovery

mmc0: cqhci: Failed to halt

mmc0: cqhci: spurious TCN for tag 0

WARNING: drivers/mmc/host/cqhci-core.c:797 at cqhci_irq+0x254/0x818, CPU#1: kworker/1:0H/24

Modules linked in:

CPU: 1 UID: 0 PID: 24 Comm: kworker/1:0H Not tainted 6.19.0-rc1-00001-g09db0998649d-dirty #204 PREEMPT

Hardware name: Rockchip RK3588 EVB1 V10 Board (DT)

Workqueue: kblockd blk_mq_run_work_fn

pstate: 604000c9 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)

pc : cqhci_irq+0x254/0x818

lr

/// 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