Re: [PATCH] xhci: Cancel cmd_timer before cleanup the command queue in xhci_hc_died()

From: Greg Kroah-Hartman
Date: Wed Nov 01 2017 - 12:03:32 EST


On Fri, Sep 29, 2017 at 05:12:47PM +0800, Jeffy Chen wrote:
> When the cmd_timer fired, it would try to access the command struct.
> So cancel it before cleanup the command queue in xhci_hc_died(), to
> avoid use-after-free reported by KASAN:
> [ 176.952537] BUG: KASAN: use-after-free in xhci_handle_command_timeout+0x68/0x224
> [ 176.960846] Write of size 4 at addr ffffffc0cbb01608 by task kworker/3:3/1680
> ...
> [ 177.180644] Freed by task 0:
> [ 177.183882] kasan_slab_free+0x90/0x15c
> [ 177.188194] kfree+0x114/0x28c
> [ 177.191630] xhci_cleanup_command_queue+0xc8/0xf8
> [ 177.196916] xhci_hc_died+0x84/0x358
>
> Fixes: d9f11ba9f107 ("xhci: Rework how we handle unresponsive or hoptlug removed hosts")
> Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
> ---

Mathias, did you miss this one? Want me to queue it up?

thanks,

greg k-h