CVE-2025-37812: usb: cdns3: Fix deadlock when using NCM gadget

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-08 · updated 2026-06-17
Weakness: CWE-667

Description

In the Linux kernel, the following vulnerability has been resolved: usb: cdns3: Fix deadlock when using NCM gadget The cdns3 driver has the same NCM deadlock as fixed in cdnsp by commit 58f2fcb3a845 ("usb: cdnsp: Fix deadlock issue during using NCM gadget"). Under PREEMPT_RT the deadlock can be readily triggered by heavy network traffic, for example using "iperf --bidir" over NCM ethernet link. The deadlock occurs because the threaded interrupt handler gets preempted by a softirq, but both are protected by the same spinlock. Prevent deadlock by disabling softirq during threaded irq handler.

Affected products

Debian Linux: 11.0
Linux kernel: from 5.4 before 5.4.293; from 5.5 before 5.10.237; from 5.11 before 5.15.181; from 5.16 before 6.1.136; from 6.2 before 6.6.89; from 6.7 before 6.12.26 — fixed in 5.10.237, 5.15.181, 5.4.293, 6.1.136, 6.12.26, 6.14.5

How to fix

Upgrade to a fixed version: Linux kernel 5.10.237, 5.15.181, 5.4.293, 6.1.136. Check the vendor advisory for mitigations.

References

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