| Message ID | 20220712135504.1055688-1-yangyingliang@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | Revert "spi: simplify devm_spi_register_controller" | expand |
On 2022/7/13 20:42, Mark Brown wrote: > On Tue, Jul 12, 2022 at 09:55:04PM +0800, Yang Yingliang wrote: >> This reverts commit 59ebbe40fb51e307032ae7f63b2749fad2d4635a. >> >> If devm_add_action() fails in devm_add_action_or_reset(), >> devm_spi_unregister() will be called, it decreases the > Please submit patches using subject lines reflecting the style for the > subsystem, this makes it easier for people to identify relevant patches. > Look at what existing commits in the area you're changing are doing and > make sure your subject lines visually resemble what they're doing. > There's no need to resubmit to fix this alone. > > Please include human readable descriptions of things like commits and > issues being discussed in e-mail in your mails, this makes them much > easier for humans to read especially when they have no internet access. > I do frequently catch up on my mail on flights or while otherwise > travelling so this is even more pressing for me than just being about > making things a bit easier to read. OK. Thanks for changing the subject to apply it, I will make my patch more readable next time. Thanks, Yang
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index dc1a324e3271..ef751ccd65be 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3130,9 +3130,9 @@ 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); } /** @@ -3151,13 +3151,22 @@ 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);
This reverts commit 59ebbe40fb51e307032ae7f63b2749fad2d4635a. 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> --- drivers/spi/spi.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)