CVE-2026-98316: ALSA: bcd2000: Fix race between rawmidi and disconnect

Severity: unknown
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: 2026-10-06 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: bcd2000: Fix race between rawmidi and disconnect Although we tried to fix the potential UAF issues at USB disconnect on bcd2000 driver, there is still an overlooked case -- namely, when a rawmidi trigger callback has been already running at USB disconnect handling, the in-flight function (e.g. bcd2000_midi_send()) could still access the URB, because the previous URB NULL-check & clearance was considered only for the URB complete callbacks, but not about the parallel rawmidi operations. For addressing the race, this patch introduced a new spinlock that covers each rawmidi operation as well as the rawmidi handling in the complete callback. The URB is cleared with the lock, so it guarantees that the pending rawmidi task already finished or a NULL check is effective.

Affected products

Linux kernel: from 5.10.270 before 5.11; from 5.15.221 before 5.16; from 6.1.188 before 6.1.189; from 6.6.157 before 6.6.158; from 6.12.109 before 6.12.112; from 6.18.50 before 6.18.54 — fixed in 5.11, 5.16, 6.1.189, 6.12.112, 6.18.54, 6.6.158

How to fix

Upgrade to a fixed version: Linux kernel 5.11, 5.16, 6.1.189, 6.12.112. Check the vendor advisory for mitigations.

References

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