[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? 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; }
