diff options
| author | Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> | 2021-05-24 09:01:55 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-24 16:22:28 +0300 |
| commit | e752dbc59e1241b13b8c4f7b6eb582862e7668fe (patch) | |
| tree | a18eeeb5e96a219a7de027691b20aa97a49ee33e /drivers/usb/gadget | |
| parent | a20dcf53ea9836387b229c4878f9559cf1b55b71 (diff) | |
| download | linux-e752dbc59e1241b13b8c4f7b6eb582862e7668fe.tar.xz | |
usb: gadget: udc: renesas_usb3: Fix a race in usb3_start_pipen()
The usb3_start_pipen() is called by renesas_usb3_ep_queue() and
usb3_request_done_pipen() so that usb3_start_pipen() is possible
to cause a race when getting usb3_first_req like below:
renesas_usb3_ep_queue()
spin_lock_irqsave()
list_add_tail()
spin_unlock_irqrestore()
usb3_start_pipen()
usb3_first_req = usb3_get_request() --- [1]
--- interrupt ---
usb3_irq_dma_int()
usb3_request_done_pipen()
usb3_get_request()
usb3_start_pipen()
usb3_first_req = usb3_get_request()
...
(the req is possible to be finished in the interrupt)
The usb3_first_req [1] above may have been finished after the interrupt
ended so that this driver caused to start a transfer wrongly. To fix this
issue, getting/checking the usb3_first_req are under spin_lock_irqsave()
in the same section.
Fixes: 746bfe63bba3 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20210524060155.1178724-1-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/udc/renesas_usb3.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c index 0c418ce50ba0..f1b35a39d1ba 100644 --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -1488,7 +1488,7 @@ static void usb3_start_pipen(struct renesas_usb3_ep *usb3_ep, struct renesas_usb3_request *usb3_req) { struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep); - struct renesas_usb3_request *usb3_req_first = usb3_get_request(usb3_ep); + struct renesas_usb3_request *usb3_req_first; unsigned long flags; int ret = -EAGAIN; u32 enable_bits = 0; @@ -1496,7 +1496,8 @@ static void usb3_start_pipen(struct renesas_usb3_ep *usb3_ep, spin_lock_irqsave(&usb3->lock, flags); if (usb3_ep->halt || usb3_ep->started) goto out; - if (usb3_req != usb3_req_first) + usb3_req_first = __usb3_get_request(usb3_ep); + if (!usb3_req_first || usb3_req != usb3_req_first) goto out; if (usb3_pn_change(usb3, usb3_ep->num) < 0) |