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From 904d88d743b0c94092c5117955eab695df8109e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>
Date: Mon, 24 Jun 2019 18:45:11 +0200
Subject: [PATCH] qmi_wwan: Fix out-of-bounds read
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Git-commit: 904d88d743b0c94092c5117955eab695df8109e8
Patch-mainline: v5.2-rc7
References: bsc#1111666

The syzbot reported

 Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xca/0x13e lib/dump_stack.c:113
  print_address_description+0x67/0x231 mm/kasan/report.c:188
  __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:317
  kasan_report+0xe/0x20 mm/kasan/common.c:614
  qmi_wwan_probe+0x342/0x360 drivers/net/usb/qmi_wwan.c:1417
  usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
  really_probe+0x281/0x660 drivers/base/dd.c:509
  driver_probe_device+0x104/0x210 drivers/base/dd.c:670
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454

Caused by too many confusing indirections and casts.
id->driver_info is a pointer stored in a long.  We want the
pointer here, not the address of it.

Thanks-to: Hillf Danton <hdanton@sina.com>
Reported-by: syzbot+b68605d7fadd21510de1@syzkaller.appspotmail.com
Cc: Kristian Evensen <kristian.evensen@gmail.com>
Fixes: e4bf63482c30 ("qmi_wwan: Add quirk for Quectel dynamic config")
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/usb/qmi_wwan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index d080f8048e52..8b4ad10cf940 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -1482,7 +1482,7 @@ static int qmi_wwan_probe(struct usb_interface *intf,
 	 * different. Ignore the current interface if the number of endpoints
 	 * equals the number for the diag interface (two).
 	 */
-	info = (void *)&id->driver_info;
+	info = (void *)id->driver_info;
 
 	if (info->data & QMI_WWAN_QUIRK_QUECTEL_DYNCFG) {
 		if (desc->bNumEndpoints == 2)
-- 
2.16.4