Commit 43cc5a0a authored by Yang Yingliang's avatar Yang Yingliang Committed by Mark Brown

spi: Fix simplification of devm_spi_register_controller

This reverts commit 59ebbe40 ("spi: simplify
devm_spi_register_controller").

If devm_add_action() fails in devm_add_action_or_reset(),
devm_spi_unregister() will be called, it decreases the
refcount of 'ctlr->dev' to 0, then it will cause uaf in
the drivers that calling spi_put_controller() in error path.

Fixes: 59ebbe40 ("spi: simplify devm_spi_register_controller")
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220712135504.1055688-1-yangyingliang@huawei.comSigned-off-by: default avatarMark Brown <broonie@kernel.org>
parent cdb0cc93
......@@ -3132,9 +3132,9 @@ int spi_register_controller(struct spi_controller *ctlr)
}
EXPORT_SYMBOL_GPL(spi_register_controller);
static void devm_spi_unregister(void *ctlr)
static void devm_spi_unregister(struct device *dev, void *res)
{
spi_unregister_controller(ctlr);
spi_unregister_controller(*(struct spi_controller **)res);
}
/**
......@@ -3153,13 +3153,22 @@ static void devm_spi_unregister(void *ctlr)
int devm_spi_register_controller(struct device *dev,
struct spi_controller *ctlr)
{
struct spi_controller **ptr;
int ret;
ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = spi_register_controller(ctlr);
if (ret)
return ret;
if (!ret) {
*ptr = ctlr;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
return ret;
}
EXPORT_SYMBOL_GPL(devm_spi_register_controller);
......
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