Messages in this thread Patch in this message | | | Subject | Re: [REGRESSION] 07ec51480b5e ("virtio_pci: use shared interrupts for virtqueues") causes crashes in guest | From | Jason Wang <> | Date | Thu, 23 Mar 2017 13:13:50 +0800 |
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On 2017年03月23日 08:30, Laura Abbott wrote: > Hi, > > Fedora has received multiple reports of crashes when running > 4.11 as a guest > > https://bugzilla.redhat.com/show_bug.cgi?id=1430297 > https://bugzilla.redhat.com/show_bug.cgi?id=1434462 > https://bugzilla.kernel.org/show_bug.cgi?id=194911 > https://bugzilla.redhat.com/show_bug.cgi?id=1433899 > > The crashes are not always consistent but they are generally > some flavor of oops or GPF in virtio related code. Multiple people > have done bisections (Thank you Thorsten Leemhuis and > Richard W.M. Jones) and found this commit to be at fault > > 07ec51480b5eb1233f8c1b0f5d7a7c8d1247c507 is the first bad commit > commit 07ec51480b5eb1233f8c1b0f5d7a7c8d1247c507 > Author: Christoph Hellwig <hch@lst.de> > Date: Sun Feb 5 18:15:19 2017 +0100 > > virtio_pci: use shared interrupts for virtqueues > > This lets IRQ layer handle dispatching IRQs to separate handlers for the > case where we don't have per-VQ MSI-X vectors, and allows us to greatly > simplify the code based on the assumption that we always have interrupt > vector 0 (legacy INTx or config interrupt for MSI-X) available, and > any other interrupt is request/freed throught the VQ, even if the > actual interrupt line might be shared in some cases. > > This allows removing a great deal of variables keeping track of the > interrupt state in struct virtio_pci_device, as we can now simply walk the > list of VQs and deal with per-VQ interrupt handlers there, and only treat > vector 0 special. > > Additionally clean up the VQ allocation code to properly unwind on error > instead of having a single global cleanup label, which is error prone, > and in this case also leads to more code. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > :040000 040000 79a8267ffb73f9d244267c5f68365305bddd4696 8832a160b978710bbd24ba6966f462b3faa27fcc M drivers > > It doesn't revert cleanly so we haven't been able to do a clean > test. Any ideas? > > Thanks, > Laura
Hello:
Can you try the attached patch to see if it solves the problem? (At least it silent KASan warnings for me).
Thanks
From 312859b596e83a2164a8430343d31fce2a5ad808 Mon Sep 17 00:00:00 2001 From: Jason Wang <jasowang@redhat.com> Date: Thu, 23 Mar 2017 13:07:16 +0800 Subject: [PATCH] virtio_pci: fix out of bound access for msix_names
Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/virtio/virtio_pci_common.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index df548a6..5905349 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -147,7 +147,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs, { struct virtio_pci_device *vp_dev = to_vp_device(vdev); const char *name = dev_name(&vp_dev->vdev.dev); - int i, err = -ENOMEM, allocated_vectors, nvectors; + int i, j, err = -ENOMEM, allocated_vectors, nvectors; unsigned flags = PCI_IRQ_MSIX; bool shared = false; u16 msix_vec; @@ -212,7 +212,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs, if (!vp_dev->msix_vector_map) goto out_disable_config_irq; - allocated_vectors = 1; /* vector 0 is the config interrupt */ + allocated_vectors = j = 1; /* vector 0 is the config interrupt */ for (i = 0; i < nvqs; ++i) { if (!names[i]) { vqs[i] = NULL; @@ -236,18 +236,19 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs, continue; } - snprintf(vp_dev->msix_names[i + 1], + snprintf(vp_dev->msix_names[j], sizeof(*vp_dev->msix_names), "%s-%s", dev_name(&vp_dev->vdev.dev), names[i]); err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec), vring_interrupt, IRQF_SHARED, - vp_dev->msix_names[i + 1], vqs[i]); + vp_dev->msix_names[j], vqs[i]); if (err) { /* don't free this irq on error */ vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR; goto out_remove_vqs; } vp_dev->msix_vector_map[i] = msix_vec; + j++; /* * Use a different vector for each queue if they are available, -- 2.7.4
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