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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,
        syzbot+91adee8d9ebb9193d22d@syzkaller.appspotmail.com,
        Pavel Skripkin <paskripkin@gmail.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.9 32/47] drivers: net: fix memory leak in peak_usb_create_dev
Date:   Thu, 15 Apr 2021 16:47:24 +0200
Message-Id: <20210415144414.497577693@linuxfoundation.org>
In-Reply-To: <20210415144413.487943796@linuxfoundation.org>
References: <20210415144413.487943796@linuxfoundation.org>
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From: Pavel Skripkin <paskripkin@gmail.com>

commit a0b96b4a62745397aee662670cfc2157bac03f55 upstream.

syzbot reported memory leak in peak_usb.
The problem was in case of failure after calling
->dev_init()[2] in peak_usb_create_dev()[1]. The data
allocated int dev_init() wasn't freed, so simple
->dev_free() call fix this problem.

backtrace:
    [<0000000079d6542a>] kmalloc include/linux/slab.h:552 [inline]
    [<0000000079d6542a>] kzalloc include/linux/slab.h:682 [inline]
    [<0000000079d6542a>] pcan_usb_fd_init+0x156/0x210 drivers/net/can/usb/peak_usb/pcan_usb_fd.c:868   [2]
    [<00000000c09f9057>] peak_usb_create_dev drivers/net/can/usb/peak_usb/pcan_usb_core.c:851 [inline] [1]
    [<00000000c09f9057>] peak_usb_probe+0x389/0x490 drivers/net/can/usb/peak_usb/pcan_usb_core.c:949

Reported-by: syzbot+91adee8d9ebb9193d22d@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/can/usb/peak_usb/pcan_usb_core.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
@@ -880,7 +880,7 @@ static int peak_usb_create_dev(const str
 	if (dev->adapter->dev_set_bus) {
 		err = dev->adapter->dev_set_bus(dev, 0);
 		if (err)
-			goto lbl_unregister_candev;
+			goto adap_dev_free;
 	}
 
 	/* get device number early */
@@ -892,6 +892,10 @@ static int peak_usb_create_dev(const str
 
 	return 0;
 
+adap_dev_free:
+	if (dev->adapter->dev_free)
+		dev->adapter->dev_free(dev);
+
 lbl_unregister_candev:
 	unregister_candev(netdev);