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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Colin Ian King <colin.king@canonical.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 170/639] staging: most: cdev: add missing check for cdev_add failure
Date:   Fri, 24 Jan 2020 10:25:40 +0100
Message-Id: <20200124093108.445964162@linuxfoundation.org>
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From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit 5ae890780e1b4d08f2c0c5d4ea96fc3928fc0ee9 ]

Currently the call to cdev_add is missing a check for failure. Fix this by
checking for failure and exiting via a new error path that ensures the
allocated comp_channel struct is kfree'd.

Detected by CoverityScan, CID#1462359 ("Unchecked return value")

Fixes: 9bc79bbcd0c5 ("Staging: most: add MOST driver's aim-cdev module")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/staging/most/cdev/cdev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/most/cdev/cdev.c b/drivers/staging/most/cdev/cdev.c
index 0b48677fa958a..27d58b55b8108 100644
--- a/drivers/staging/most/cdev/cdev.c
+++ b/drivers/staging/most/cdev/cdev.c
@@ -453,7 +453,9 @@ static int comp_probe(struct most_interface *iface, int channel_id,
 	c->devno = MKDEV(comp.major, current_minor);
 	cdev_init(&c->cdev, &channel_fops);
 	c->cdev.owner = THIS_MODULE;
-	cdev_add(&c->cdev, c->devno, 1);
+	retval = cdev_add(&c->cdev, c->devno, 1);
+	if (retval < 0)
+		goto err_free_c;
 	c->iface = iface;
 	c->cfg = cfg;
 	c->channel_id = channel_id;
@@ -485,6 +487,7 @@ error_create_device:
 	list_del(&c->list);
 error_alloc_kfifo:
 	cdev_del(&c->cdev);
+err_free_c:
 	kfree(c);
 error_alloc_channel:
 	ida_simple_remove(&comp.minor_id, current_minor);
-- 
2.20.1