4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jorge Sanjuan Garcia jorge.sanjuangarcia@duagon.com
commit 0f28ada1fbf0054557cddcdb93ad17f767105208 upstream.
When calling mcb_bus_add_devices(), both mcb devices and the mcb bus will attempt to attach a device to a driver because they share the same bus_type. This causes an issue when trying to cast the container of the device to mcb_device struct using to_mcb_device(), leading to a wrong cast when the mcb_bus is added. A crash occurs when freing the ida resources as the bus numbering of mcb_bus gets confused with the is_added flag on the mcb_device struct.
The only reason for this cast was to keep an is_added flag on the mcb_device struct that does not seem necessary. The function device_attach() handles already bound devices and the mcb subsystem does nothing special with this is_added flag so remove it completely.
Fixes: 18d288198099 ("mcb: Correctly initialize the bus's device") Cc: stable stable@kernel.org Signed-off-by: Jorge Sanjuan Garcia jorge.sanjuangarcia@duagon.com Co-developed-by: Jose Javier Rodriguez Barbarin JoseJavier.Rodriguez@duagon.com Signed-off-by: Jose Javier Rodriguez Barbarin JoseJavier.Rodriguez@duagon.com Link: https://lore.kernel.org/r/20230906114901.63174-2-JoseJavier.Rodriguez@duagon... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mcb/mcb-core.c | 10 +++------- drivers/mcb/mcb-parse.c | 2 -- include/linux/mcb.h | 1 - 3 files changed, 3 insertions(+), 10 deletions(-)
--- a/drivers/mcb/mcb-core.c +++ b/drivers/mcb/mcb-core.c @@ -392,17 +392,13 @@ EXPORT_SYMBOL_GPL(mcb_free_dev);
static int __mcb_bus_add_devices(struct device *dev, void *data) { - struct mcb_device *mdev = to_mcb_device(dev); int retval;
- if (mdev->is_added) - return 0; - retval = device_attach(dev); - if (retval < 0) + if (retval < 0) { dev_err(dev, "Error adding device (%d)\n", retval); - - mdev->is_added = true; + return retval; + }
return 0; } --- a/drivers/mcb/mcb-parse.c +++ b/drivers/mcb/mcb-parse.c @@ -98,8 +98,6 @@ static int chameleon_parse_gdd(struct mc mdev->mem.end = mdev->mem.start + size - 1; mdev->mem.flags = IORESOURCE_MEM;
- mdev->is_added = false; - ret = mcb_device_register(bus, mdev); if (ret < 0) goto err; --- a/include/linux/mcb.h +++ b/include/linux/mcb.h @@ -66,7 +66,6 @@ static inline struct mcb_bus *to_mcb_bus struct mcb_device { struct device dev; struct mcb_bus *bus; - bool is_added; struct mcb_driver *driver; u16 id; int inst;