published August 5, 2026
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
vmalloc'd 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)