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mcb: fix error handling in mcb_alloc_bus()

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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: 5d9e2ab9fe ("mcb: Implement bus->dev.release callback")
Fixes: 18d2881980 ("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/32e160cf6864ce77f9d62948338e24db9fd8ead9.1630931319.git.johannes.thumshirn@wdc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dan Carpenter 2021-09-06 21:35:48 +09:00 committed by Greg Kroah-Hartman
parent 8d753db5c2
commit 25a1433216
1 changed files with 6 additions and 6 deletions
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12
drivers/mcb/mcb-core.c
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@ -275,8 +275,8 @@ struct mcb_bus *mcb_alloc_bus(struct device *carrier)
bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL);
if (bus_nr < 0) { if (bus_nr < 0) {
rc = bus_nr; kfree(bus);
goto err_free; return ERR_PTR(bus_nr);
} }
bus->bus_nr = bus_nr; bus->bus_nr = bus_nr;
@ -291,12 +291,12 @@ struct mcb_bus *mcb_alloc_bus(struct device *carrier)
dev_set_name(&bus->dev, "mcb:%d", bus_nr); dev_set_name(&bus->dev, "mcb:%d", bus_nr);
rc = device_add(&bus->dev); rc = device_add(&bus->dev);
if (rc) if (rc)
goto err_free; goto err_put;
return bus; return bus;
err_free:
put_device(carrier); err_put:
kfree(bus); put_device(&bus->dev);
return ERR_PTR(rc); return ERR_PTR(rc);
} }
EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, MCB); EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, MCB);