lkml.org 
[lkml]   [2022]   [Aug]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.4 004/389] ALSA: bcd2000: Fix a UAF bug on the error path of probing
    Date
    From: Zheyu Ma <zheyuma97@gmail.com>

    commit ffb2759df7efbc00187bfd9d1072434a13a54139 upstream.

    When the driver fails in snd_card_register() at probe time, it will free
    the 'bcd2k->midi_out_urb' before killing it, which may cause a UAF bug.

    The following log can reveal it:

    [ 50.727020] BUG: KASAN: use-after-free in bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000]
    [ 50.727623] Read of size 8 at addr ffff88810fab0e88 by task swapper/4/0
    [ 50.729530] Call Trace:
    [ 50.732899] bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000]

    Fix this by adding usb_kill_urb() before usb_free_urb().

    Fixes: b47a22290d58 ("ALSA: MIDI driver for Behringer BCD2000 USB device")
    Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/20220715010515.2087925-1-zheyuma97@gmail.com
    Signed-off-by: Takashi Iwai <tiwai@suse.de>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    sound/usb/bcd2000/bcd2000.c | 3 ++-
    1 file changed, 2 insertions(+), 1 deletion(-)

    --- a/sound/usb/bcd2000/bcd2000.c
    +++ b/sound/usb/bcd2000/bcd2000.c
    @@ -348,7 +348,8 @@ static int bcd2000_init_midi(struct bcd2
    static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
    struct usb_interface *interface)
    {
    - /* usb_kill_urb not necessary, urb is aborted automatically */
    + usb_kill_urb(bcd2k->midi_out_urb);
    + usb_kill_urb(bcd2k->midi_in_urb);

    usb_free_urb(bcd2k->midi_out_urb);
    usb_free_urb(bcd2k->midi_in_urb);

    \
     
     \ /
      Last update: 2022-08-23 13:12    [W:4.468 / U:0.188 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site