[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v2] usb/xchi: avoid trigger assertion if guest w
From: |
Philippe Mathieu-Daudé |
Subject: |
Re: [Qemu-devel] [PATCH v2] usb/xchi: avoid trigger assertion if guest write wrong epid |
Date: |
Tue, 30 Apr 2019 09:43:58 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 |
On 4/30/19 8:21 AM, 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>
Tested-by: Philippe Mathieu-Daudé <address@hidden>
> ---
> v1 -> v2:
> 1) update the description, include the full backtrace
> 2) remove unnecessary check: 'reg == 0'
>
> ---
> hw/usb/hcd-xhci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
> index ec28bee..d8472b4 100644
> --- a/hw/usb/hcd-xhci.c
> +++ b/hw/usb/hcd-xhci.c
> @@ -3137,7 +3137,7 @@ static void xhci_doorbell_write(void *ptr, hwaddr reg,
> streamid = (val >> 16) & 0xffff;
> if (reg > xhci->numslots) {
> DPRINTF("xhci: bad doorbell %d\n", (int)reg);
> - } else if (epid > 31) {
> + } else if (epid == 0 || epid > 31) {
> DPRINTF("xhci: bad doorbell %d write: 0x%x\n",
> (int)reg, (uint32_t)val);
> } else {
>