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authorAlan Stern <stern@rowland.harvard.edu>2019-04-22 11:16:04 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-25 11:11:41 +0200
commitc114944d7d67f24e71562fcfc18d550ab787e4d4 (patch)
tree04f2d076bcc3f9a00ebf3395bfb90e21cc5eaf31 /drivers/w1/masters
parentef61eb43ada6c1d6b94668f0f514e4c268093ff3 (diff)
USB: w1 ds2490: Fix bug caused by improper use of altsetting array
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@rowland.harvard.edu> Reported-and-tested-by: syzbot+d65f673b847a1a96cdba@syzkaller.appspotmail.com CC: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/masters')
-rw-r--r--drivers/w1/masters/ds2490.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 0f4ecfcdb549..a9fb77585272 100644
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -1016,15 +1016,15 @@ static int ds_probe(struct usb_interface *intf,
/* 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);