Re: [Qemu-devel] [PATCH v2] usb/xchi: avoid trigger assertion if guest write wrong epid

[Gerd Hoffmann]

On Tue, Apr 30, 2019 at 02:21:41PM +0800, Longpeng(Mike) wrote:
> From: Longpeng <address@hidden>
> 
> we found the following core in our environment:
> 0  0x00007fc6b06c2237 in raise ()
> 1  0x00007fc6b06c3928 in abort ()
> 2  0x00007fc6b06bb056 in __assert_fail_base ()
> 3  0x00007fc6b06bb102 in __assert_fail ()
> 4  0x0000000000702e36 in xhci_kick_ep (...)
> 5  0x000000000047897a in memory_region_write_accessor (...)
> 6  0x000000000047767f in access_with_adjusted_size (...)
> 7  0x000000000047944d in memory_region_dispatch_write (...)
> (address@hidden, address@hidden, data=1648892416,
> address@hidden, address@hidden)
> 8  0x000000000042df17 in address_space_write_continue (...)
> 10 0x000000000043084d in address_space_rw (...)
> 11 0x000000000047451b in kvm_cpu_exec (address@hidden)
> 12 0x000000000045dcf5 in qemu_kvm_cpu_thread_fn (arg=0x1ab11b0)
> 13 0x0000000000870631 in qemu_thread_start (address@hidden)
> 14 0x00000000008959a7 in thread_entry_for_hotfix (pthread_cb=<optimized out>)
> 15 0x00007fc6b0a60dd5 in start_thread ()
> 16 0x00007fc6b078a59d in clone ()
> 
> (gdb) f 5
> 5  0x000000000047897a in memory_region_write_accessor (...)
> 529       mr->ops->write(mr->opaque, addr, tmp, size);
> (gdb) p /x tmp
> $9 = 0x62481a00 <-- last byte 0x00 is @epid
> 
> xhci_doorbell_write() already check the upper bound of @slotid an @epid,
> it also need to check the lower bound.
> 
> Cc: Gonglei <address@hidden>
> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
> Signed-off-by: Longpeng <address@hidden>

Added to usb queue.

thanks,
  Gerd