linux-kernel - [PATCH v4] usb: gadget: udc: remove pointer dereference after free

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Date:   Fri, 10 Mar 2017 15:39:32 -0600
From:   "Gustavo A. R. Silva" <garsilva@...eddedor.com>
To:     Felipe Balbi <balbi@...nel.org>
Cc:     Michal Nazarewicz <mina86@...a86.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        gregkh@...uxfoundation.org, heikki.krogerus@...ux.intel.com,
        mail@...oabal.eu, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Peter Senna Tschudin <peter.senna@...il.com>,
        "Gustavo A. R. Silva" <garsilva@...eddedor.com>
Subject: [PATCH v4] usb: gadget: udc: remove pointer dereference after free

Remove pointer dereference after free.

Addresses-Coverity-ID: 1091173
Acked-by: Michal Nazarewicz <mina86@...a86.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@...eddedor.com>
---
Changes in v2:
 Move pointer dereference before pci_pool_free()
 Set pointer to NULL after free

Changes in v3:
 Remove 'td->next = 0x00' inside for loop.
 Remove unnecessary pointer nullification after free.

Changes in v4:
 Fix line-wrapping in previous patch.

 drivers/usb/gadget/udc/pch_udc.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/usb/gadget/udc/pch_udc.c b/drivers/usb/gadget/udc/pch_udc.c
index a97da64..8a365aa 100644
--- a/drivers/usb/gadget/udc/pch_udc.c
+++ b/drivers/usb/gadget/udc/pch_udc.c
@@ -1523,7 +1523,6 @@ static void pch_udc_free_dma_chain(struct pch_udc_dev *dev,
 		td = phys_to_virt(addr);
 		addr2 = (dma_addr_t)td->next;
 		pci_pool_free(dev->data_requests, td, addr);
-		td->next = 0x00;
 		addr = addr2;
 	}
 	req->chain_len = 1;
-- 
2.5.0