spi: oc-tiny: switch to managed controller allocation

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

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.

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

Fixes: ce792580ea ("spi: add OpenCores tiny SPI driver")
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260719010014.3163356-1-fanwu01@zju.edu.cn
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Fan Wu 2026-07-19 01:00:13 +00:00 • committed by Mark Brown
commit d710f43ce3
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0