On Fri, 31 Dec 2021 at 03:31, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > [Trimmed CC: list] > > On Thu, Dec 30, 2021 at 04:49:18PM -0800, syzbot wrote: > > Hello, > > > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > > KASAN: slab-out-of-bounds Write in usb_hcd_poll_rh_status > ... > > Tested on: > > > > commit: eec4df26 Merge tag 's390-5.16-6' of git://git.kernel.o.. > > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > I'm glad to see that the git tree is reported properly, but the commit > label is too short. The reproducer bug report had exactly the opposite > problems! It said: > > > syzbot has found a reproducer for the following issue on: > > > > HEAD commit: eec4df26e24e Merge tag 's390-5.16-6' of git://git.kernel.o.. > > git tree: upstream > > Andrey or Dmitry? Can you guys unify these two outputs to make both > lines correct always? Hi Alan, This got lost on the mailing list. Filed https://github.com/google/syzkaller/issues/3147 to track this request. Thanks > Moving on... Important lines from the console log: > > [ 76.919138][ T4081] usb usb9: usbdev_do_ioctl: BULK > [ 76.924966][ T4081] usb usb9: usbfs: process 4081 (syz-executor189) did not claim interface 0 before use > [ 76.935186][ T4081] usb usb9: ep1 int-in, length 1, timeout 9 > [ 76.941355][ T4099] usb usb9: opened by process 4099: syz-executor189 > [ 76.942606][ T4087] usb usb9: usbdev_do_ioctl: BULK > [ 76.949968][ C1] > ================================================================== > [ 76.950070][ C1] BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x376/0x780 > [ 76.950102][ C1] Write of size 2 at addr ffff8880121ae230 by task syz-executor189/4087 > > It's hard to tell what's really happening. The suspicious part is the > "length 1" combined with the "Write of size 2" -- but they refer to > different processes! > > Maybe this diagnostic patch will help a little. > > Alan Stern > > #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ eec4df26e24e > > Index: usb-devel/drivers/usb/core/devio.c > =================================================================== > --- usb-devel.orig/drivers/usb/core/devio.c > +++ usb-devel/drivers/usb/core/devio.c > @@ -109,7 +109,7 @@ struct async { > u8 bulk_status; > }; > > -static bool usbfs_snoop; > +static bool usbfs_snoop = true; > module_param(usbfs_snoop, bool, S_IRUGO | S_IWUSR); > MODULE_PARM_DESC(usbfs_snoop, "true to log all usbfs traffic"); > > Index: usb-devel/drivers/usb/core/hcd.c > =================================================================== > --- usb-devel.orig/drivers/usb/core/hcd.c > +++ usb-devel/drivers/usb/core/hcd.c > @@ -809,8 +809,10 @@ static int rh_queue_status (struct usb_h > unsigned len = 1 + (urb->dev->maxchild / 8); > > spin_lock_irqsave (&hcd_root_hub_lock, flags); > + dev_info(hcd->self.controller, "rh_queue_status: len %d tblen %d\n", > + len, urb->transfer_buffer_length); > if (hcd->status_urb || urb->transfer_buffer_length < len) { > - dev_dbg (hcd->self.controller, "not queuing rh status urb\n"); > + dev_info(hcd->self.controller, "not queuing rh status urb\n"); > retval = -EINVAL; > goto done; > } >
