[PATCH AUTOSEL 4.18 117/136] EDAC, i7core: Fix memleaks and use-after-free on probe and remove

From: Sasha Levin
Date: Sun Sep 16 2018 - 23:03:04 EST


From: Johan Hovold <johan@xxxxxxxxxx>

[ Upstream commit 6c974d4dfafe5e9ee754f2a6fba0eb1864f1649e ]

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.

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx>
Fixes: 356f0a30860d ("i7core_edac: change the mem allocation scheme to make Documentation/kobject.txt happy")
Link: http://lkml.kernel.org/r/20180612124335.6420-2-johan@xxxxxxxxxx
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
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 8ed4dd9c571b..8e120bf60624 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