[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20190506143053.056065786@linuxfoundation.org>
Date: Mon, 6 May 2019 16:32:54 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Alan Stern <stern@...land.harvard.edu>,
syzbot+d65f673b847a1a96cdba@...kaller.appspotmail.com
Subject: [PATCH 4.9 23/62] USB: w1 ds2490: Fix bug caused by improper use of altsetting array
From: Alan Stern <stern@...land.harvard.edu>
commit c114944d7d67f24e71562fcfc18d550ab787e4d4 upstream.
The syzkaller USB fuzzer spotted a slab-out-of-bounds bug in the
ds2490 driver. This bug is caused by improper use of the altsetting
array in the usb_interface structure (the array's entries are not
always stored in numerical order), combined with a naive assumption
that all interfaces probed by the driver will have the expected number
of altsettings.
The bug can be fixed by replacing references to the possibly
non-existent intf->altsetting[alt] entry with the guaranteed-to-exist
intf->cur_altsetting entry.
Signed-off-by: Alan Stern <stern@...land.harvard.edu>
Reported-and-tested-by: syzbot+d65f673b847a1a96cdba@...kaller.appspotmail.com
CC: <stable@...r.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
drivers/w1/masters/ds2490.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -1039,15 +1039,15 @@ static int ds_probe(struct usb_interface
/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
alt = 3;
err = usb_set_interface(dev->udev,
- intf->altsetting[alt].desc.bInterfaceNumber, alt);
+ intf->cur_altsetting->desc.bInterfaceNumber, alt);
if (err) {
dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
"for %d interface: err=%d.\n", alt,
- intf->altsetting[alt].desc.bInterfaceNumber, err);
+ intf->cur_altsetting->desc.bInterfaceNumber, err);
goto err_out_clear;
}
- iface_desc = &intf->altsetting[alt];
+ iface_desc = intf->cur_altsetting;
if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
pr_info("Num endpoints=%d. It is not DS9490R.\n",
iface_desc->desc.bNumEndpoints);
Powered by blists - more mailing lists