From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:48351) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gRZHy-0007yk-De for qemu-devel@nongnu.org; Tue, 27 Nov 2018 04:04:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gRZHu-00009u-Dt for qemu-devel@nongnu.org; Tue, 27 Nov 2018 04:04:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52650) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gRZHs-00007T-M2 for qemu-devel@nongnu.org; Tue, 27 Nov 2018 04:04:10 -0500 Date: Tue, 27 Nov 2018 10:04:00 +0100 From: Cornelia Huck Message-ID: <20181127100400.186f7f33.cohuck@redhat.com> In-Reply-To: <20181127084143.1113-1-armbru@redhat.com> References: <20181127084143.1113-1-armbru@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH for-3.1] vfio-helpers: Fix qemu_vfio_open_pci() crash List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: qemu-devel@nongnu.org, fam@euphon.net, pbonzini@redhat.com, coli@redhat.com, stefanha@redhat.com On Tue, 27 Nov 2018 09:41:43 +0100 Markus Armbruster wrote: > qemu_vfio_open_common() initializes s->lock only after passing s to > qemu_vfio_dma_map() via qemu_vfio_init_ramblock(). > qemu_vfio_dma_map() tries to lock the uninitialized lock and crashes. > > Fix by initializing s->lock first. > > RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1645840 > Fixes: 418026ca43bc2626db092d7558258f9594366f28 > Cc: qemu-stable@nongnu.org > Signed-off-by: Markus Armbruster > --- > Compile-tested only, as I lack suitable hardware. Cong Li (cc'ed) is > going to test it for real. It looks obvious enough to me to put it > into -rc3 without waiting for the test results. We can also wait and > put it into -rc4. This looks obvious to me as well. > > util/vfio-helpers.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c > index 1d9272efa4..cccc9cd42e 100644 > --- a/util/vfio-helpers.c > +++ b/util/vfio-helpers.c > @@ -411,13 +411,13 @@ static int qemu_vfio_init_ramblock(const char *block_name, void *host_addr, > > static void qemu_vfio_open_common(QEMUVFIOState *s) > { > + qemu_mutex_init(&s->lock); > s->ram_notifier.ram_block_added = qemu_vfio_ram_block_added; > s->ram_notifier.ram_block_removed = qemu_vfio_ram_block_removed; > ram_block_notifier_add(&s->ram_notifier); > s->low_water_mark = QEMU_VFIO_IOVA_MIN; > s->high_water_mark = QEMU_VFIO_IOVA_MAX; > qemu_ram_foreach_block(qemu_vfio_init_ramblock, s); > - qemu_mutex_init(&s->lock); > } > > /** Reviewed-by: Cornelia Huck