lkml.org 
[lkml]   [2016]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 063/117] usb: hub: do not clear BOS field during reset device
    Date
    4.4-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Du, Changbin <changbin.du@intel.com>

    commit d8f00cd685f5c8e0def8593e520a7fef12c22407 upstream.

    In function usb_reset_and_verify_device, the old BOS descriptor may
    still be used before allocating a new one. (usb_unlocked_disable_lpm
    function uses it under the situation that it fails to disable lpm.)
    So we cannot set the udev->bos to NULL before that, just keep what it
    was. It will be overwrite when allocating a new one.

    Crash log:
    BUG: unable to handle kernel NULL pointer dereference at
    0000000000000010
    IP: [<ffffffff8171f98d>] usb_enable_link_state+0x2d/0x2f0
    Call Trace:
    [<ffffffff8171ed5b>] ? usb_set_lpm_timeout+0x12b/0x140
    [<ffffffff8171fcd1>] usb_enable_lpm+0x81/0xa0
    [<ffffffff8171fdd8>] usb_disable_lpm+0xa8/0xc0
    [<ffffffff8171fe1c>] usb_unlocked_disable_lpm+0x2c/0x50
    [<ffffffff81723933>] usb_reset_and_verify_device+0xc3/0x710
    [<ffffffff8172c4ed>] ? usb_sg_wait+0x13d/0x190
    [<ffffffff81724743>] usb_reset_device+0x133/0x280
    [<ffffffff8179ccd1>] usb_stor_port_reset+0x61/0x70
    [<ffffffff8179cd68>] usb_stor_invoke_transport+0x88/0x520

    Signed-off-by: Du, Changbin <changbin.du@intel.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/usb/core/hub.c | 8 +++++---
    1 file changed, 5 insertions(+), 3 deletions(-)

    --- a/drivers/usb/core/hub.c
    +++ b/drivers/usb/core/hub.c
    @@ -5386,7 +5386,6 @@ static int usb_reset_and_verify_device(s
    }

    bos = udev->bos;
    - udev->bos = NULL;

    for (i = 0; i < SET_CONFIG_TRIES; ++i) {

    @@ -5479,8 +5478,11 @@ done:
    usb_set_usb2_hardware_lpm(udev, 1);
    usb_unlocked_enable_lpm(udev);
    usb_enable_ltm(udev);
    - usb_release_bos_descriptor(udev);
    - udev->bos = bos;
    + /* release the new BOS descriptor allocated by hub_port_init() */
    + if (udev->bos != bos) {
    + usb_release_bos_descriptor(udev);
    + udev->bos = bos;
    + }
    return 0;

    re_enumerate:

    \
     
     \ /
      Last update: 2016-02-15 00:41    [W:4.220 / U:0.140 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site