CVE-2026-64409

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.