[PATCH 4.19 002/140] usb: gadget: pch_udc: fix use after free

Greg Kroah-Hartman
2019-12-16T18:01:42Z

From: Gustavo A. R. Silva <gustavo@embeddedor.com>

commit 66d1b0c0580b7f1b1850ee4423f32ac42afa2e92 upstream.

Remove pointer dereference after free.

pci_pool_free doesn't care about contents of td.
It's just a void* for it

Addresses-Coverity-ID: 1091173 ("Use after free")
Cc: stable@vger.kernel.org
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20191106202821.GA20347@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/usb/gadget/udc/pch_udc.c
+++ b/drivers/usb/gadget/udc/pch_udc.c
@@ -1520,7 +1520,6 @@ static void pch_udc_free_dma_chain(struc
td = phys_to_virt(addr);
addr2 = (dma_addr_t)td->next;
dma_pool_free(dev->data_requests, td, addr);
- td->next = 0x00;
addr = addr2;
}
req->chain_len = 1;