Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-64409
Linux Linux — Bluetooth: btmtksdio: fix infinite loop in btmtksdio_txrx_work()
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0016 4.9 —
AFFECTED
Product Versions Fixed
Linux 26270bc189ea4b5a8356ec99561357fc87f00b32 – —
Linux 5.17 – 6.1.178
TIMELINE
Jul 19 Reserved by Linux
Jul 25 Published (CNA: Linux)
Sep 4 ENRICHED — CVE-2026-64409 (Linux). Received CVSS 5.5 and CPE data from NVD.
Description
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| July 19, 2026 | Reserved | Reserved by Linux |
| July 25, 2026 | Published | Published (CNA: Linux) |
| September 4, 2026 | ENRICHED | ENRICHED — CVE-2026-64409 (Linux). Received CVSS 5.5 and CPE data from NVD. |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 26270bc189ea4b5a8356ec99561357fc87f00b32 | — |
| Linux | Linux | — | 5.17 | 6.1.178 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-64409 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.