releases/4.11.2/ib-core-fix-sysfs-registration-error-flow.patch

   1 From b312be3d87e4c80872cbea869e569175c5eb0f9a Mon Sep 17 00:00:00 2001
   2 From: Jack Morgenstein <jackm@dev.mellanox.co.il>
   3 Date: Sun, 19 Mar 2017 10:55:57 +0200
   4 Subject: IB/core: Fix sysfs registration error flow
   5
   6 From: Jack Morgenstein <jackm@dev.mellanox.co.il>
   7
   8 commit b312be3d87e4c80872cbea869e569175c5eb0f9a upstream.
   9
  10 The kernel commit cited below restructured ib device management
  11 so that the device kobject is initialized in ib_alloc_device.
  12
  13 As part of the restructuring, the kobject is now initialized in
  14 procedure ib_alloc_device, and is later added to the device hierarchy
  15 in the ib_register_device call stack, in procedure
  16 ib_device_register_sysfs (which calls device_add).
  17
  18 However, in the ib_device_register_sysfs error flow, if an error
  19 occurs following the call to device_add, the cleanup procedure
  20 device_unregister is called. This call results in the device object
  21 being deleted -- which results in various use-after-free crashes.
  22
  23 The correct cleanup call is device_del -- which undoes device_add
  24 without deleting the device object.
  25
  26 The device object will then (correctly) be deleted in the
  27 ib_register_device caller's error cleanup flow, when the caller invokes
  28 ib_dealloc_device.
  29
  30 Fixes: 55aeed06544f6 ("IB/core: Make ib_alloc_device init the kobject")
  31 Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
  32 Signed-off-by: Leon Romanovsky <leon@kernel.org>
  33 Signed-off-by: Doug Ledford <dledford@redhat.com>
  34 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  35
  36 ---
  37  drivers/infiniband/core/sysfs.c |    2 +-
  38  1 file changed, 1 insertion(+), 1 deletion(-)
  39
  40 --- a/drivers/infiniband/core/sysfs.c
  41 +++ b/drivers/infiniband/core/sysfs.c
  42 @@ -1301,7 +1301,7 @@ err_put:
  43         free_port_list_attributes(device);
  44
  45  err_unregister:
  46 -       device_unregister(class_dev);
  47 +       device_del(class_dev);
  48
  49  err:
  50         return ret;