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From 9aea9b6cc78d2b99b23d84fb2e0bc6e464c6569e Mon Sep 17 00:00:00 2001
From: Bin Liu <b-liu@ti.com>
Date: Mon, 30 Apr 2018 11:20:54 -0500
Subject: [PATCH] usb: musb: trace: fix NULL pointer dereference in musb_g_tx()
Git-commit: 9aea9b6cc78d2b99b23d84fb2e0bc6e464c6569e
Patch-mainline: v4.17-rc4
References: bsc#1051510

The usb_request pointer could be NULL in musb_g_tx(), where the
tracepoint call would trigger the NULL pointer dereference failure when
parsing the members of the usb_request pointer.

Move the tracepoint call to where the usb_request pointer is already
checked to solve the issue.

Fixes: fc78003e5345 ("usb: musb: gadget: add usb-request tracepoints")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/usb/musb/musb_gadget.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index e564695c6c8d..71c5835ea9cd 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -417,7 +417,6 @@ void musb_g_tx(struct musb *musb, u8 epnum)
 	req = next_request(musb_ep);
 	request = &req->request;
 
-	trace_musb_req_tx(req);
 	csr = musb_readw(epio, MUSB_TXCSR);
 	musb_dbg(musb, "<== %s, txcsr %04x", musb_ep->end_point.name, csr);
 
@@ -456,6 +455,8 @@ void musb_g_tx(struct musb *musb, u8 epnum)
 		u8	is_dma = 0;
 		bool	short_packet = false;
 
+		trace_musb_req_tx(req);
+
 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
 			is_dma = 1;
 			csr |= MUSB_TXCSR_P_WZC_BITS;
-- 
2.18.0