From: Vladis Dronov <vdronov@redhat.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alan Stern <stern@rowland.harvard.edu>,
Oliver Neukum <oneukum@suse.com>,
Hans de Goede <hdegoede@redhat.com>,
syzkaller@googlegroups.com, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: stable <stable@vger.kernel.org>, Vladis Dronov <vdronov@redhat.com>
Subject: [PATCH] usb: usbfs: fix crash in check_ctrlrecip()->usb_find_alt_setting()
Date: Tue, 25 Sep 2018 14:22:42 +0200 [thread overview]
Message-ID: <20180925122242.10950-1-vdronov@redhat.com> (raw)
ps->dev->actconfig can be NULL and cause NULL-deref in usb_find_alt_setting()
before c9a4cb204e9e. fix this anyway by checking that ps->dev->actconfig is not
NULL, so usb_find_alt_setting() is not called with a known-bad argument.
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Reported-by: syzbot+19c3aaef85a89d451eac@syzkaller.appspotmail.com
---
drivers/usb/core/devio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 6ce77b33da61..26047620b003 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -824,7 +824,7 @@ static int check_ctrlrecip(struct usb_dev_state *ps, unsigned int requesttype,
* class specification, which we always want to allow as it is used
* to query things like ink level, etc.
*/
- if (requesttype == 0xa1 && request == 0) {
+ if (requesttype == 0xa1 && request == 0 && ps->dev->actconfig) {
alt_setting = usb_find_alt_setting(ps->dev->actconfig,
index >> 8, index & 0xff);
if (alt_setting
--
2.14.4
next reply other threads:[~2018-09-25 12:23 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-25 12:22 Vladis Dronov [this message]
2018-09-25 14:14 ` [PATCH] usb: usbfs: fix crash in check_ctrlrecip()->usb_find_alt_setting() Alan Stern
2018-09-25 14:55 ` Vladis Dronov
2018-09-25 15:15 ` Alan Stern
2018-09-25 15:17 ` Andrey Konovalov
2018-09-25 17:54 ` Alan Stern
2018-09-25 18:55 ` Vladis Dronov
2018-09-25 20:44 ` Alan Stern
2018-09-26 8:22 ` Vladis Dronov
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