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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Johan Hovold <johan@kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-edac <linux-edac@vger.kernel.org>,
        Borislav Petkov <bp@suse.de>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL 4.18 117/136] EDAC, i7core: Fix memleaks and
 use-after-free on probe and remove
Thread-Topic: [PATCH AUTOSEL 4.18 117/136] EDAC, i7core: Fix memleaks and
 use-after-free on probe and remove
Thread-Index: AQHUTjK4uiSSHV8+XkKCMK/o8x/AcA==
Date:   Mon, 17 Sep 2018 03:01:25 +0000
Message-ID: <20180917030006.245495-117-alexander.levin@microsoft.com>
References: <20180917030006.245495-1-alexander.levin@microsoft.com>
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From: Johan Hovold <johan@kernel.org>

[ 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@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
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@kernel.org
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 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_c=
tl_info *mci)
=20
 	rc =3D device_add(pvt->addrmatch_dev);
 	if (rc < 0)
-		return rc;
+		goto err_put_addrmatch;
=20
 	if (!pvt->is_registered) {
 		pvt->chancounts_dev =3D kzalloc(sizeof(*pvt->chancounts_dev),
 					      GFP_KERNEL);
 		if (!pvt->chancounts_dev) {
-			put_device(pvt->addrmatch_dev);
-			device_del(pvt->addrmatch_dev);
-			return -ENOMEM;
+			rc =3D -ENOMEM;
+			goto err_del_addrmatch;
 		}
=20
 		pvt->chancounts_dev->type =3D &all_channel_counts_type;
@@ -1199,9 +1198,18 @@ static int i7core_create_sysfs_devices(struct mem_ct=
l_info *mci)
=20
 		rc =3D 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;
 }
=20
 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");
=20
 	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);
 }
=20
 /*************************************************************************=
***
--=20
2.17.1