CVE-2026-64573

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: qca: fix NVM tag length underflow in TLV parser

In the TLV_TYPE_NVM branch of qca_tlv_check_data() the tag loop bound is while (idx < length - sizeof(struct tlv_type_nvm)). length is a signed int from the firmware TLV header and sizeof(struct tlv_type_nvm) is a size_t (12), so length is converted to size_t and any firmware-supplied length < 12 makes the subtraction wrap to a huge value. The loop body then reads a 12-byte struct tlv_type_nvm past the end of the short vmallocd firmware buffer (and the EDL_TAG_ID_* handlers can write past it).

Rewrite the bound as idx + sizeof(struct tlv_type_nvm) <= length; both operands are non-negative, so it no longer underflows and a length too small for one record correctly skips the loop.

BUG: KASAN: vmalloc-out-of-bounds in qca_download_firmware.isra.0 (drivers/bluetooth/btqca.c:421) Read of size 2 at addr ffffc900000e5004 by task kworker/u9:0/52 Workqueue: hci0 hci_power_on Call Trace: … kasan_report (mm/kasan/report.c:595) qca_download_firmware.isra.0 (drivers/bluetooth/btqca.c:421 drivers/bluetooth/btqca.c:617) qca_uart_setup (drivers/bluetooth/btqca.c:948) qca_setup (drivers/bluetooth/hci_qca.c:2029) hci_uart_setup (drivers/bluetooth/hci_ldisc.c:438) hci_dev_open_sync (net/bluetooth/hci_sync.c:5227) hci_power_on (net/bluetooth/hci_core.c:920) process_one_work (kernel/workqueue.c:3322) worker_thread (kernel/workqueue.c:3486) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245)

Affected Software

References

• https://git.kernel.org/stable/c/4fcfb5b2c736785464ff9745f94c6726c5ee2d85
• https://git.kernel.org/stable/c/59fd2f075bca94f030c7c78e94878ea0803d7690
• https://git.kernel.org/stable/c/70354dbb5f72d9a76da7b031de3cbaf6c7d8fc24
• https://git.kernel.org/stable/c/a087ed960fce54e9302796229e9d545bbc9bcd4a
• https://git.kernel.org/stable/c/c90164ca0f7036942ba088eb7ea8d3f6c2352020