This is the follow-up of the driver_override generalization in [1], converting the remaining 11 busses and removing the now-unused driver_set_override() helper.
All of them (except AP, which has a different race condition) are prone to the potential UAF described in [2], caused by accessing the driver_override field from their corresponding match() callback. In order to address this, the generalized driver_override field in struct device is protected with a spinlock. The driver-core provides accessors, such as device_match_driver_override(), device_has_driver_override() and device_set_driver_override(), which all ensure proper locking internally. Additionally, the driver-core provides a driver_override flag in struct bus_type, which, once enabled, automatically registers generic sysfs callbacks, allowing userspace to modify the driver_override field. SPI and AP are a bit special; both print "\n" when driver_override is not set, whereas all other buses (and thus the driver-core) produce "(null)\n" in this case. Hence, SPI and AP do not take advantage of the driver_override flag in struct bus_type; AP additionally maintains a counter in its custom sysfs store(). Technically, we could support a custom fallback string when driver_override is unset in struct bus_type, but only SPI would benefit from this, since AP has additional custom logic in store() anyways. (I'm not sure if there are userspace programs that strictly rely on this; driverctl seems to check for both, but I rather not break some userspace tool I'm not aware of. :) This series is based on v7.0-rc5 with no additional dependencies, hence those patches can be picked up by subsystems individually. [1] https://lore.kernel.org/driver-core/[email protected]/ [2] https://bugzilla.kernel.org/show_bug.cgi?id=220789 [3] https://gitlab.com/driverctl/driverctl/-/blob/0.121/driverctl?ref_type=tags#L99 Danilo Krummrich (12): amba: use generic driver_override infrastructure bus: fsl-mc: use generic driver_override infrastructure cdx: use generic driver_override infrastructure hv: vmbus: use generic driver_override infrastructure PCI: use generic driver_override infrastructure platform/wmi: use generic driver_override infrastructure rpmsg: use generic driver_override infrastructure vdpa: use generic driver_override infrastructure s390/cio: use generic driver_override infrastructure s390/ap: use generic driver_override infrastructure spi: use generic driver_override infrastructure driver core: remove driver_set_override() drivers/amba/bus.c | 37 +++------------ drivers/base/driver.c | 75 ------------------------------ drivers/bus/fsl-mc/fsl-mc-bus.c | 43 +++-------------- drivers/cdx/cdx.c | 40 ++-------------- drivers/hv/vmbus_drv.c | 36 ++------------ drivers/pci/pci-driver.c | 11 +++-- drivers/pci/pci-sysfs.c | 28 ----------- drivers/pci/probe.c | 1 - drivers/platform/wmi/core.c | 36 ++------------ drivers/rpmsg/qcom_glink_native.c | 2 - drivers/rpmsg/rpmsg_core.c | 43 +++-------------- drivers/rpmsg/virtio_rpmsg_bus.c | 1 - drivers/s390/cio/cio.h | 5 -- drivers/s390/cio/css.c | 34 ++------------ drivers/s390/crypto/ap_bus.c | 34 +++++++------- drivers/s390/crypto/ap_bus.h | 1 - drivers/s390/crypto/ap_queue.c | 24 +++------- drivers/spi/spi.c | 19 +++----- drivers/vdpa/vdpa.c | 48 ++----------------- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 4 +- drivers/vfio/pci/vfio_pci_core.c | 5 +- drivers/xen/xen-pciback/pci_stub.c | 6 ++- include/linux/amba/bus.h | 5 -- include/linux/cdx/cdx_bus.h | 4 -- include/linux/device/driver.h | 2 - include/linux/fsl/mc.h | 4 -- include/linux/hyperv.h | 5 -- include/linux/pci.h | 6 --- include/linux/rpmsg.h | 4 -- include/linux/spi/spi.h | 5 -- include/linux/vdpa.h | 4 -- include/linux/wmi.h | 4 -- 32 files changed, 88 insertions(+), 488 deletions(-) base-commit: c369299895a591d96745d6492d4888259b004a9e -- 2.53.0
