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| author | Heiko Stuebner <heiko.stuebner@theobroma-systems.com> | 2021-01-27 11:39:19 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-05 10:28:38 +0100 |
| commit | f670e9f9c8cac716c3506c6bac9e997b27ad441a (patch) | |
| tree | b336d7b6fce08e144137f5b4aaf7f689095642ff /drivers | |
| parent | 0e5a3c8284a30f4c43fd81d7285528ece74563b5 (diff) | |
| download | lwn-f670e9f9c8cac716c3506c6bac9e997b27ad441a.tar.gz lwn-f670e9f9c8cac716c3506c6bac9e997b27ad441a.zip | |
usb: dwc2: Fix endpoint direction check in ep_from_windex
dwc2_hsotg_process_req_status uses ep_from_windex() to retrieve
the endpoint for the index provided in the wIndex request param.
In a test-case with a rndis gadget running and sending a malformed
packet to it like:
dev.ctrl_transfer(
0x82, # bmRequestType
0x00, # bRequest
0x0000, # wValue
0x0001, # wIndex
0x00 # wLength
)
it is possible to cause a crash:
[ 217.533022] dwc2 ff300000.usb: dwc2_hsotg_process_req_status: USB_REQ_GET_STATUS
[ 217.559003] Unable to handle kernel read from unreadable memory at virtual address 0000000000000088
...
[ 218.313189] Call trace:
[ 218.330217] ep_from_windex+0x3c/0x54
[ 218.348565] usb_gadget_giveback_request+0x10/0x20
[ 218.368056] dwc2_hsotg_complete_request+0x144/0x184
This happens because ep_from_windex wants to compare the endpoint
direction even if index_to_ep() didn't return an endpoint due to
the direction not matching.
The fix is easy insofar that the actual direction check is already
happening when calling index_to_ep() which will return NULL if there
is no endpoint for the targeted direction, so the offending check
can go away completely.
Fixes: c6f5c050e2a7 ("usb: dwc2: gadget: add bi-directional endpoint support")
Cc: stable@vger.kernel.org
Reported-by: Gerhard Klostermeier <gerhard.klostermeier@syss.de>
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Link: https://lore.kernel.org/r/20210127103919.58215-1-heiko@sntech.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/dwc2/gadget.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index 0a0d11151cfb..ad4c94366dad 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -1543,7 +1543,6 @@ static void dwc2_hsotg_complete_oursetup(struct usb_ep *ep, static struct dwc2_hsotg_ep *ep_from_windex(struct dwc2_hsotg *hsotg, u32 windex) { - struct dwc2_hsotg_ep *ep; int dir = (windex & USB_DIR_IN) ? 1 : 0; int idx = windex & 0x7F; @@ -1553,12 +1552,7 @@ static struct dwc2_hsotg_ep *ep_from_windex(struct dwc2_hsotg *hsotg, if (idx > hsotg->num_of_eps) return NULL; - ep = index_to_ep(hsotg, idx, dir); - - if (idx && ep->dir_in != dir) - return NULL; - - return ep; + return index_to_ep(hsotg, idx, dir); } /** |