Linux Kernel up to 7.1.3 Btmtksdio btmtksdio_txrx_work infinite loop

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5.9	$0-$5k	0.79

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.1.177/6.6.144/6.12.95/6.18.38/7.1.3. This impacts the function btmtksdio_txrx_work of the component Btmtksdio. Executing a manipulation can lead to infinite loop. The identification of this vulnerability is CVE-2026-64409. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.1.177/6.6.144/6.12.95/6.18.38/7.1.3. This vulnerability affects the function btmtksdio_txrx_work of the component Btmtksdio. The manipulation with an unknown input leads to a infinite loop vulnerability. The CWE definition for the vulnerability is CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-64409 since 07/19/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch f6682c23b6fac4780d297ae4662053d17e58fd52/466540e045d01fcacf383a5beb8a2dad2fc53a26/7b429d611060e87752e848851815537963726493/0039bdde36b23ccf1196635f1d52c5490481544d/0f0a83e26a9c7fd4b243c315ce07161d2496d83d/a257407e2bbbb099ed427719a50563f67fa366d8 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.177
• 6.6.144
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
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• 6.12.94
• 6.12.95
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
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• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.0
VulDB Meta Temp Score: 5.9

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.178/6.6.145/6.12.96/6.18.39/7.1.4/7.2-rc1
Patch: f6682c23b6fac4780d297ae4662053d17e58fd52/466540e045d01fcacf383a5beb8a2dad2fc53a26/7b429d611060e87752e848851815537963726493/0039bdde36b23ccf1196635f1d52c5490481544d/0f0a83e26a9c7fd4b243c315ce07161d2496d83d/a257407e2bbbb099ed427719a50563f67fa366d8

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
09/05/2026 +42 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64409 (🔒)
GCVE (CVE): GCVE-0-2026-64409
GCVE (VulDB): GCVE-100-383194

Entryinfo

Created: 07/25/2026 18:23
Updated: 09/05/2026 02:42
Changes: 07/25/2026 18:23 (59), 09/05/2026 02:42 (11)
Complete: 🔍
Cache ID: 216::103

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