From: Dan Carpenter dan.carpenter@oracle.com
commit 25a1433216489de4abc889910f744e952cb6dbae upstream.
There are two bugs: 1) If ida_simple_get() fails then this code calls put_device(carrier) but we haven't yet called get_device(carrier) and probably that leads to a use after free. 2) After device_initialize() then we need to use put_device() to release the bus. This will free the internal resources tied to the device and call mcb_free_bus() which will free the rest.
Fixes: 5d9e2ab9fea4 ("mcb: Implement bus->dev.release callback") Fixes: 18d288198099 ("mcb: Correctly initialize the bus's device") Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Johannes Thumshirn jth@kernel.org Link: https://lore.kernel.org/r/32e160cf6864ce77f9d62948338e24db9fd8ead9.163093131... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mcb/mcb-core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/mcb/mcb-core.c +++ b/drivers/mcb/mcb-core.c @@ -280,8 +280,8 @@ struct mcb_bus *mcb_alloc_bus(struct dev
bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); if (bus_nr < 0) { - rc = bus_nr; - goto err_free; + kfree(bus); + return ERR_PTR(bus_nr); }
bus->bus_nr = bus_nr; @@ -296,12 +296,12 @@ struct mcb_bus *mcb_alloc_bus(struct dev dev_set_name(&bus->dev, "mcb:%d", bus_nr); rc = device_add(&bus->dev); if (rc) - goto err_free; + goto err_put;
return bus; -err_free: - put_device(carrier); - kfree(bus); + +err_put: + put_device(&bus->dev); return ERR_PTR(rc); } EXPORT_SYMBOL_GPL(mcb_alloc_bus);