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authorLi Hangjing2019-06-03 08:15:24 +0200
committerMichael S. Tsirkin2019-06-16 22:16:52 +0200
commit240e647a14df9677b3a501f7b8b870e40aac3fd5 (patch)
tree9a2fc253fb81e4e4aab6615c558969c10f0eea26 /hw/virtio/vhost.c
parentdocs/vhost-user.json: some firmware.json copy leftovers (diff)
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vhost: fix vhost_log size overflow during migration
When a guest which doesn't support multiqueue is migrated with a multi queues vhost-user-blk deivce, a crash will occur like: 0 qemu_memfd_alloc (name=<value optimized out>, size=562949953421312, seals=<value optimized out>, fd=0x7f87171fe8b4, errp=0x7f87171fe8a8) at util/memfd.c:153 1 0x00007f883559d7cf in vhost_log_alloc (size=70368744177664, share=true) at hw/virtio/vhost.c:186 2 0x00007f88355a0758 in vhost_log_get (listener=0x7f8838bd7940, enable=1) at qemu-2-12/hw/virtio/vhost.c:211 3 vhost_dev_log_resize (listener=0x7f8838bd7940, enable=1) at hw/virtio/vhost.c:263 4 vhost_migration_log (listener=0x7f8838bd7940, enable=1) at hw/virtio/vhost.c:787 5 0x00007f88355463d6 in memory_global_dirty_log_start () at memory.c:2503 6 0x00007f8835550577 in ram_init_bitmaps (f=0x7f88384ce600, opaque=0x7f8836024098) at migration/ram.c:2173 7 ram_init_all (f=0x7f88384ce600, opaque=0x7f8836024098) at migration/ram.c:2192 8 ram_save_setup (f=0x7f88384ce600, opaque=0x7f8836024098) at migration/ram.c:2219 9 0x00007f88357a419d in qemu_savevm_state_setup (f=0x7f88384ce600) at migration/savevm.c:1002 10 0x00007f883579fc3e in migration_thread (opaque=0x7f8837530400) at migration/migration.c:2382 11 0x00007f8832447893 in start_thread () from /lib64/libpthread.so.0 12 0x00007f8832178bfd in clone () from /lib64/libc.so.6 This is because vhost_get_log_size() returns a overflowed vhost-log size. In this function, it uses the uninitialized variable vqs->used_phys and vqs->used_size to get the vhost-log size. Signed-off-by: Li Hangjing <lihangjing@baidu.com> Reviewed-by: Xie Yongji <xieyongji@baidu.com> Reviewed-by: Chai Wen <chaiwen@baidu.com> Message-Id: <20190603061524.24076-1-lihangjing@baidu.com> Cc: qemu-stable@nongnu.org Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/virtio/vhost.c')
-rw-r--r--hw/virtio/vhost.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 60747a6f93..bc899fc60e 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -131,6 +131,11 @@ static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
}
for (i = 0; i < dev->nvqs; ++i) {
struct vhost_virtqueue *vq = dev->vqs + i;
+
+ if (!vq->used_phys && !vq->used_size) {
+ continue;
+ }
+
vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys,
range_get_last(vq->used_phys, vq->used_size));
}
@@ -168,6 +173,11 @@ static uint64_t vhost_get_log_size(struct vhost_dev *dev)
}
for (i = 0; i < dev->nvqs; ++i) {
struct vhost_virtqueue *vq = dev->vqs + i;
+
+ if (!vq->used_phys && !vq->used_size) {
+ continue;
+ }
+
uint64_t last = vq->used_phys + vq->used_size - 1;
log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
}