[PATCH 5.19 676/717] usb: musb: Fix musb_gadget.c rxstate overflow bug

Greg Kroah-Hartman
2022-10-22T08:48:13Z

From: Robin Guo <guoweibin@inspur.com>

[ Upstream commit eea4c860c3b366369eff0489d94ee4f0571d467d ]

The usb function device call musb_gadget_queue() adds the passed
request to musb_ep::req_list,If the (request->length > musb_ep->packet_sz)
and (is_buffer_mapped(req) return false),the rxstate() will copy all data
in fifo to request->buf which may cause request->buf out of bounds.

Fix it by add the length check :
fifocnt = min_t(unsigned, request->length - request->actual, fifocnt);

Signed-off-by: Robin Guo <guoweibin@inspur.com>
Link: https://lore.kernel.org/r/20220906102119.1b071d07a8391ff115e6d1ef@inspur.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/musb/musb_gadget.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 51274b87f46c..dc67fff8e941 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -760,6 +760,9 @@ static void rxstate(struct musb *musb, struct musb_request *req)
musb_writew(epio, MUSB_RXCSR, csr);

buffer_aint_mapped:
+ fifo_count = min_t(unsigned int,
+ request->length - request->actual,
+ (unsigned int)fifo_count);
musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
(request->buf + request->actual));
request->actual += fifo_count;
--
2.35.1