[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v2] virtio-net: Always check for guest header le
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH v2] virtio-net: Always check for guest header length |
Date: |
Mon, 22 Jul 2019 08:26:54 +0100 |
User-agent: |
Mutt/1.12.0 (2019-05-25) |
On Fri, Jul 19, 2019 at 03:21:15PM +0000, Oleinik, Alexander wrote:
> While fuzzing the virtio-net tx vq, I ran into an assertion failure due
> to iov_copy offsets larger than the total iov size. Though there is
> a check to cover this, it does not execute when !n->has_vnet_hdr. This
> change always copies the guest header into the mhdr buffer and checks its
> length, even if mhdr is not needed.
>
> The call stack for the assertion failure:
>
> #8 in __assert_fail (libc.so.6+0x300f1)
> #9 in iov_copy iov.c:266:5
> #10 in virtio_net_flush_tx virtio-net.c:2073:23
> #11 in virtio_net_tx_bh virtio-net.c:2197:11
> #12 in aio_bh_poll async.c:118:13
> #13 in aio_dispatch aio-posix.c:460:5
> #14 in aio_ctx_dispatch async.c:261:5
> #15 in g_main_context_dispatch (libglib-2.0.so.0+0x4df2d)
> #16 in glib_pollfds_poll main-loop.c:213:9
> #17 in os_host_main_loop_wait main-loop.c:236
> #18 in main_loop_wait main-loop.c:512
> #19 in virtio_net_tx_fuzz virtio-net-fuzz.c:160:3
>
> Signed-off-by: Alexander Oleinik <address@hidden>
> ---
> hw/net/virtio-net.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
Reviewed-by: Stefan Hajnoczi <address@hidden>
signature.asc
Description: PGP signature