[PATCH 2/3] usb: chipidea: udc: improve error handling on ep_queue

From: eu
Date: Fri Sep 18 2015 - 13:30:36 EST


From: "Felipe F. Tonello" <eu@xxxxxxxxxxxxxxxxx>

_ep_queue() didn't check for errors when using add_td_to_list()
which can fail if dma_pool_alloc fails, thus causing a kernel
panic when lastnode->ptr is NULL.

Signed-off-by: Felipe F. Tonello <eu@xxxxxxxxxxxxxxxxx>
---

Changes for v2:
- Use separate patch for cleanups.

drivers/usb/chipidea/udc.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index c936c72..7169113e 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -435,19 +435,27 @@ static int _hardware_enqueue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
if (hwreq->req.dma % PAGE_SIZE)
pages--;

- if (rest == 0)
- add_td_to_list(hwep, hwreq, 0);
+ if (rest == 0) {
+ ret = add_td_to_list(hwep, hwreq, 0);
+ if (ret < 0)
+ goto done;
+ }

while (rest > 0) {
unsigned count = min(hwreq->req.length - hwreq->req.actual,
(unsigned)(pages * CI_HDRC_PAGE_SIZE));
- add_td_to_list(hwep, hwreq, count);
+ ret = add_td_to_list(hwep, hwreq, count);
+ if (ret < 0)
+ goto done;
rest -= count;
}

if (hwreq->req.zero && hwreq->req.length
- && (hwreq->req.length % hwep->ep.maxpacket == 0))
- add_td_to_list(hwep, hwreq, 0);
+ && (hwreq->req.length % hwep->ep.maxpacket == 0)) {
+ ret = add_td_to_list(hwep, hwreq, 0);
+ if (ret < 0)
+ goto done;
+ }

firstnode = list_first_entry(&hwreq->tds, struct td_node, td);

--
2.1.4

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