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[PATCH v2 1/2] virtio-pci: add check for vdev in virtio_pci_isr_read
From: |
Yuri Benditovich |
Subject: |
[PATCH v2 1/2] virtio-pci: add check for vdev in virtio_pci_isr_read |
Date: |
Mon, 15 Mar 2021 13:59:36 +0200 |
https://bugzilla.redhat.com/show_bug.cgi?id=1743098
This commit completes the solution of segfault in hot unplug flow
(by commit ccec7e9603f446fe75c6c563ba335c00cfda6a06).
Added missing check for vdev in virtio_pci_isr_read.
Typical stack of crash:
virtio_pci_isr_read ../hw/virtio/virtio-pci.c:1365 with proxy-vdev = 0
memory_region_read_accessor at ../softmmu/memory.c:442
access_with_adjusted_size at ../softmmu/memory.c:552
memory_region_dispatch_read1 at ../softmmu/memory.c:1420
memory_region_dispatch_read at ../softmmu/memory.c:1449
flatview_read_continue at ../softmmu/physmem.c:2822
flatview_read at ../softmmu/physmem.c:2862
address_space_read_full at ../softmmu/physmem.c:2875
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
---
hw/virtio/virtio-pci.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 883045a223..4a3dcee771 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1364,9 +1364,14 @@ static uint64_t virtio_pci_isr_read(void *opaque, hwaddr
addr,
{
VirtIOPCIProxy *proxy = opaque;
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
- uint64_t val = qatomic_xchg(&vdev->isr, 0);
- pci_irq_deassert(&proxy->pci_dev);
+ uint64_t val;
+
+ if (vdev == NULL) {
+ return 0;
+ }
+ val = qatomic_xchg(&vdev->isr, 0);
+ pci_irq_deassert(&proxy->pci_dev);
return val;
}
--
2.17.1