In the Linux kernel, the following vulnerability has been resolved: spi: davinci: switch to managed controller allocation The controller i

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

spi: davinci: switch to managed controller allocation

The controller is allocated with the non-managed spi_alloc_host() while
the interrupt is registered with devm_request_threaded_irq(). During
removal, spi_bitbang_stop() only unregisters the controller; the
subsequent spi_controller_put() then frees the controller together with
its embedded davinci_spi devdata, which is the IRQ handler's dev_id.
The devm_request_threaded_irq() release action (free_irq()), which
drains the handler, does not run until after .remove() returns. A late
or latched interrupt can therefore reach davinci_spi_irq() and
dereference already-freed memory.

Switch to devm_spi_alloc_host() so that the devres LIFO order releases
the controller only after free_irq() has drained the handler, and drop
the now-redundant spi_controller_put() from .remove(). The probe error
path is simplified to direct returns.

The clock is acquired with devm_clk_get_enabled(), which is registered
after the IRQ and thus released before it by the devres LIFO order.
Drain the interrupt explicitly with devm_free_irq() before disabling the
controller so that a late interrupt cannot access the registers of a
clock-gated controller.

This issue was found by an in-house static analysis tool.