[PATCH 2/2] EDAC: i7core: fix memleaks and use-after-free on probe and remove

[Johan Hovold]

Make sure to free and deregister the addrmatch and chancounts devices
allocated during probe in all error paths. Also fix use-after-free in a
probe error path and in the remove success path where the devices were
being put before before deregistration.

Fixes: 356f0a30860d ("i7core_edac: change the mem allocation scheme to make 
Documentation/kobject.txt happy")
Cc: stable <sta...@vger.kernel.org>     # 3.6
Cc: Mauro Carvalho Chehab <mche...@kernel.org>
Signed-off-by: Johan Hovold <jo...@kernel.org>
---
 drivers/edac/i7core_edac.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/edac/i7core_edac.c b/drivers/edac/i7core_edac.c
index 8c5540160a23..23e441dbaf49 100644
--- a/drivers/edac/i7core_edac.c
+++ b/drivers/edac/i7core_edac.c
@@ -1177,15 +1177,14 @@ static int i7core_create_sysfs_devices(struct 
mem_ctl_info *mci)
 
        rc = device_add(pvt->addrmatch_dev);
        if (rc < 0)
-               return rc;
+               goto err_put_addrmatch;
 
        if (!pvt->is_registered) {
                pvt->chancounts_dev = kzalloc(sizeof(*pvt->chancounts_dev),
                                              GFP_KERNEL);
                if (!pvt->chancounts_dev) {
-                       put_device(pvt->addrmatch_dev);
-                       device_del(pvt->addrmatch_dev);
-                       return -ENOMEM;
+                       rc = -ENOMEM;
+                       goto err_del_addrmatch;
                }
 
                pvt->chancounts_dev->type = &all_channel_counts_type;
@@ -1199,9 +1198,18 @@ static int i7core_create_sysfs_devices(struct 
mem_ctl_info *mci)
 
                rc = device_add(pvt->chancounts_dev);
                if (rc < 0)
-                       return rc;
+                       goto err_put_chancounts;
        }
        return 0;
+
+err_put_chancounts:
+       put_device(pvt->chancounts_dev);
+err_del_addrmatch:
+       device_del(pvt->addrmatch_dev);
+err_put_addrmatch:
+       put_device(pvt->addrmatch_dev);
+
+       return rc;
 }
 
 static void i7core_delete_sysfs_devices(struct mem_ctl_info *mci)
@@ -1211,11 +1219,11 @@ static void i7core_delete_sysfs_devices(struct 
mem_ctl_info *mci)
        edac_dbg(1, "\n");
 
        if (!pvt->is_registered) {
-               put_device(pvt->chancounts_dev);
                device_del(pvt->chancounts_dev);
+               put_device(pvt->chancounts_dev);
        }
-       put_device(pvt->addrmatch_dev);
        device_del(pvt->addrmatch_dev);
+       put_device(pvt->addrmatch_dev);
 }
 
 /****************************************************************************
-- 
2.17.1