CVE-2026-46140
Received Received - Intake
Bluetooth: btmtk USB HCI WMT Event Length Validation Flaw

Publication date: 2026-05-28

Last updated on: 2026-05-28

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btmtk: validate WMT event SKB length before struct access btmtk_usb_hci_wmt_sync() casts the WMT event response SKB data to struct btmtk_hci_wmt_evt (7 bytes) and struct btmtk_hci_wmt_evt_funcc (9 bytes) without first checking that the SKB contains enough data. A short firmware response causes out-of-bounds reads from SKB tailroom. Use skb_pull_data() to validate and advance past the base WMT event header. For the FUNC_CTRL case, pull the additional status field bytes before accessing them.
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Meta Information
Published
2026-05-28
Last Modified
2026-05-28
Generated
2026-05-28
AI Q&A
2026-05-28
EPSS Evaluated
N/A
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux_kernel linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's Bluetooth component, specifically in the btmtk driver. The function btmtk_usb_hci_wmt_sync() improperly casts the WMT event response SKB data to certain structures without first verifying that the SKB contains enough data. This lack of validation can lead to out-of-bounds reads when the firmware response is shorter than expected.

The issue arises because the code assumes the SKB data length is sufficient for the structures it casts to, but if the data is shorter, it reads beyond the buffer's boundary, potentially causing memory access errors.


How can this vulnerability impact me? :

This vulnerability can cause out-of-bounds memory reads in the Linux kernel Bluetooth driver, which may lead to system instability, crashes, or potentially expose sensitive kernel memory contents.

While the description does not specify exploitation details, out-of-bounds reads can sometimes be leveraged by attackers to gain information about kernel memory layout or cause denial of service.


What immediate steps should I take to mitigate this vulnerability?

The vulnerability has been resolved by validating the WMT event SKB length before struct access in the Linux kernel Bluetooth btmtk driver.

To mitigate this vulnerability immediately, update your Linux kernel to a version that includes the fix where skb_pull_data() is used to validate and advance past the base WMT event header, ensuring that the SKB contains enough data before accessing it.


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