From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53539) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g04Jh-0003CV-47 for qemu-devel@nongnu.org; Wed, 12 Sep 2018 08:32:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g04Je-0001kM-0S for qemu-devel@nongnu.org; Wed, 12 Sep 2018 08:32:21 -0400 Received: from mail-pg1-x542.google.com ([2607:f8b0:4864:20::542]:44133) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1g04Jd-0001jL-CN for qemu-devel@nongnu.org; Wed, 12 Sep 2018 08:32:17 -0400 Received: by mail-pg1-x542.google.com with SMTP id r1-v6so985439pgp.11 for ; Wed, 12 Sep 2018 05:32:16 -0700 (PDT) From: Li Qiang Date: Wed, 12 Sep 2018 05:32:09 -0700 Message-Id: <1536755529-2709-1-git-send-email-liq3ea@gmail.com> Subject: [Qemu-devel] [PATCH] memory region: check the old.mmio.read status List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mst@redhat.com, ehabkost@redhat.com, marcandre.lureau@gmail.com, lersek@redhat.com, peter.maydell@linaro.org, pbonzini@redhat.com, ppandit@redhat.com Cc: qemu-devel@nongnu.org, Li Qiang To avoid NULL-deref for the devices without read callbacks Signed-off-by: Li Qiang --- memory.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/memory.c b/memory.c index 9b73892768..48d025426b 100644 --- a/memory.c +++ b/memory.c @@ -406,6 +406,10 @@ static MemTxResult memory_region_oldmmio_read_accessor(MemoryRegion *mr, { uint64_t tmp; + if (!mr->ops->old_mmio.read[ctz32(size)]) { + return MEMTX_DECODE_ERROR; + } + tmp = mr->ops->old_mmio.read[ctz32(size)](mr->opaque, addr); if (mr->subpage) { trace_memory_region_subpage_read(get_cpu_index(), mr, addr, tmp, size); -- 2.11.0