| From 031b558dfe13d222f4c5468ba81b9eb84a62ffb7 Mon Sep 17 00:00:00 2001 |
| From: Jack Morgenstein <jackm@dev.mellanox.co.il> |
| Date: Sun, 19 Mar 2017 10:55:57 +0200 |
| Subject: [PATCH] IB/core: Fix sysfs registration error flow |
| |
| commit b312be3d87e4c80872cbea869e569175c5eb0f9a upstream. |
| |
| The kernel commit cited below restructured ib device management |
| so that the device kobject is initialized in ib_alloc_device. |
| |
| As part of the restructuring, the kobject is now initialized in |
| procedure ib_alloc_device, and is later added to the device hierarchy |
| in the ib_register_device call stack, in procedure |
| ib_device_register_sysfs (which calls device_add). |
| |
| However, in the ib_device_register_sysfs error flow, if an error |
| occurs following the call to device_add, the cleanup procedure |
| device_unregister is called. This call results in the device object |
| being deleted -- which results in various use-after-free crashes. |
| |
| The correct cleanup call is device_del -- which undoes device_add |
| without deleting the device object. |
| |
| The device object will then (correctly) be deleted in the |
| ib_register_device caller's error cleanup flow, when the caller invokes |
| ib_dealloc_device. |
| |
| Fixes: 55aeed06544f6 ("IB/core: Make ib_alloc_device init the kobject") |
| Cc: <stable@vger.kernel.org> # v4.2+ |
| Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> |
| Signed-off-by: Leon Romanovsky <leon@kernel.org> |
| Signed-off-by: Doug Ledford <dledford@redhat.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c |
| index 15defefecb4f..115f68cd914d 100644 |
| --- a/drivers/infiniband/core/sysfs.c |
| +++ b/drivers/infiniband/core/sysfs.c |
| @@ -1301,7 +1301,7 @@ err_put: |
| free_port_list_attributes(device); |
| |
| err_unregister: |
| - device_unregister(class_dev); |
| + device_del(class_dev); |
| |
| err: |
| return ret; |
| -- |
| 2.12.0 |
| |