• Takashi Iwai's avatar
    ALSA: bcd2000: Add a sanity check for invalid EPs · 73e6a383
    Takashi Iwai authored
    commit 6815a0b4 upstream.
    As syzkaller spotted, currently bcd2000 driver submits a URB with the
    fixed EP without checking whether it's actually available, which may
    result in a kernel warning like:
      usb 1-1: BOGUS urb xfer, pipe 1 != type 3
      ------------[ cut here ]------------
      WARNING: CPU: 0 PID: 1846 at drivers/usb/core/urb.c:449
      Modules linked in:
      CPU: 0 PID: 1846 Comm: kworker/0:2 Not tainted
      4.14.0-rc2-42613-g1488251d1a98 #238
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
      Workqueue: usb_hub_wq hub_event
      Call Trace:
       bcd2000_init_device sound/usb/bcd2000/bcd2000.c:289
       bcd2000_init_midi sound/usb/bcd2000/bcd2000.c:345
       bcd2000_probe+0xe64/0x19e0 sound/usb/bcd2000/bcd2000.c:406
       usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
    This patch adds a sanity check of validity of EPs at the device
    initialization phase for avoiding the call with an invalid EP.
    Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
    Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>