From: Yang Yingliang yangyingliang@huawei.com
[ Upstream commit 43cc5a0afe4184a7fafe1eba32b5a11bb69c9ce0 ]
This reverts commit 59ebbe40fb51 ("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: 59ebbe40fb51 ("spi: simplify devm_spi_register_controller") Signed-off-by: Yang Yingliang yangyingliang@huawei.com Reviewed-by: Conor Dooley conor.dooley@microchip.com Link: https://lore.kernel.org/r/20220712135504.1055688-1-yangyingliang@huawei.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index e1065768c537..6a8850e62078 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3068,9 +3068,9 @@ 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); }
/** @@ -3089,13 +3089,22 @@ 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);