CVE-2026-90089: Bluetooth: btnxpuart: Validate the FW dump header length

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-17 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btnxpuart: Validate the FW dump header length nxp_process_fw_dump() pulls the ACL header off the frame and then reads seq_num and buf_len from a struct nxp_fw_dump_hdr placed at skb->data, without checking that the ACL payload is long enough to contain it. h4_recv_buf() collects HCI_ACL_HDR_SIZE bytes of header followed by the number of payload bytes named in that header, so skb->len is 4 + dlen with dlen supplied by the controller and possibly smaller than the 8 byte dump header, or zero. A short frame with connection handle 0xfff therefore reads both fields from beyond the received data. Beyond the read itself, buf_len is what terminates a dump: a value of zero makes the driver call hci_devcd_complete() and reset the controller, so a truncated frame can end a dump early. Use skb_pull_data() to validate and pull the FW dump header before accessing its fields. Warn and reject the chunk if the header is truncated.

Affected products

Linux kernel: 6.15 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

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