CVE-2026-64409

Medium

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btmtksdio: fix infinite loop in btmtksdio_txrx_work() Every once in a while we see a hung btmtksdio_flush() task: INFO: task kworker/u17:0:189 blocked for more than 122 seconds. __cancel_work_timer+0x3f4/0x460 cancel_work_sync+0x1c/0x2c btmtksdio_flush+0x2c/0x40 hci_dev_open_sync+0x10c4/0x2190 [..] It all boils down to incorrect time_is_before_jiffies() usage in btmtksdio_txrx_work(). The btmtksdio_txrx_work() loop is expected to be terminated if running for longer than 5*HZ. However the timeout check is twisted: time_is_before_jiffies(old_jiffies + 5*HZ) evaluates to true when old_jiffies + 5*HZ is in the past i.e. when a timeout has occurred. Using OR with time_is_before_jiffies(txrx_timeout) means that: - before the 5-second timeout: the condition is `int_status || false`, so it loops as long as there are pending interrupts. - after the 5-second timeout: the condition becomes `int_status || true`, which is always true. When the loop becomes infinite btmtksdio_txrx_work() loop never terminates and never releases the SDIO host. Fix loop termination condition to actually enforce a 5*HZ timeout.

Package Linux Kernel
Published 2026-07-25
Last modified 2026-09-04
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-835

CVE-2026-64409 is a Infinite Loop vulnerability

What is Infinite Loop?

The product contains an iteration that does not exit even when it should. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.17 and later are affected. Fixed in 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 and their respective stable series.

Affected from
≥ 5.17
Fixed in
✓ 6.1.178 6.1.x ✓ 6.6.145 6.6.x ✓ 6.12.96 6.12.x ✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

6 total
Showing 5 of 6 references View all on NVD

Frequently asked questions

  • What is CVE-2026-64409?

    CVE-2026-64409 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Infinite Loop flaw (CWE-835) . It affects Linux kernel versions from 5.17 onward and has been patched in 6.1.178, 6.6.145, 6.12.96 and others. CVE-2026-64409 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-64409?

    CVE-2026-64409 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-64409?

    Yes. CVE-2026-64409 has been patched. Fixed versions include 6.1.178, 6.6.145, 6.12.96 and others. If you are running Linux kernel 5.17 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-64409 actively exploited?

    No. CVE-2026-64409 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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