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From:   Suwan Kim <suwan.kim027@gmail.com>
To:     shuah@kernel.org, gregkh@linuxfoundation.org
Cc:     linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        julia.lawall@lip6.fr, valentina.manea.m@gmail.com,
        Suwan Kim <suwan.kim027@gmail.com>,
        kbuild test robot <lkp@intel.com>
Subject: [PATCH] =?UTF-8?q?usbip:=C2=A0Fix=20free=20of=20unallocated=20mem?= =?UTF-8?q?ory=20in=20vhci=20tx?=
Date:   Mon, 21 Oct 2019 23:24:14 +0900
Message-Id: <20191021142414.27164-1-suwan.kim027@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

iso_buffer should be set to NULL after use and free in the while loop.
In the case of isochronous URB in the while loop, iso_buffer is
allocated and after sending it to server, buffer is deallocated. And
then, if the next URB in the while loop is not a isochronous pipe,
iso_buffer still holds the previously deallocated buffer address and
kfree tries to free wrong buffer address.

Fixes: ea44d190764b (“usbip: Implement SG support to vhci-hcd and stub driver”)
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
---
 drivers/usb/usbip/vhci_tx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c
index c3803785f6ef..b290e810d11b 100644
--- a/drivers/usb/usbip/vhci_tx.c
+++ b/drivers/usb/usbip/vhci_tx.c
@@ -73,6 +73,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 		memset(&pdu_header, 0, sizeof(pdu_header));
 		memset(&msg, 0, sizeof(msg));
 		memset(&iov, 0, sizeof(iov));
+		iso_buffer = NULL;
 
 		usbip_dbg_vhci_tx("setup txdata urb seqnum %lu\n",
 				  priv->seqnum);
-- 
2.21.0