This is a note to let you know that I've just added the patch titled

USB: w1 ds2490: Fix bug caused by improper use of altsetting array

to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From c114944d7d67f24e71562fcfc18d550ab787e4d4 Mon Sep 17 00:00:00 2001

From: Alan Stern stern@rowland.harvard.edu Date: Mon, 22 Apr 2019 11:16:04 -0400 Subject: 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 --- drivers/w1/masters/ds2490.c | 6 +++--- 1 file 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);