[libvirt] [PULL 3/3] virtio-blk: fix out-of-bounds access to bitmap in notify_guest_bh
From: Li Hangjing <lihangjing(a)baidu.com>
When the number of a virtio-blk device's virtqueues is larger than
BITS_PER_LONG, the out-of-bounds access to bitmap[ ] will occur.
Fixes: e21737ab15 ("virtio-blk: multiqueue batch notify")
Cc: qemu-stable(a)nongnu.org
Cc: Stefan Hajnoczi <stefanha(a)redhat.com>
Signed-off-by: Li Hangjing <lihangjing(a)baidu.com>
Reviewed-by: Xie Yongji <xieyongji(a)baidu.com>
Reviewed-by: Chai Wen <chaiwen(a)baidu.com>
Message-id: 20191216023050.48620-1-lihangjing(a)baidu.com
Message-Id: <20191216023050.48620-1-lihangjing(a)baidu.com>
Signed-off-by: Stefan Hajnoczi <stefanha(a)redhat.com>
---
hw/block/dataplane/virtio-blk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 119906a5fe..1b52e8159c 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -67,7 +67,7 @@ static void notify_guest_bh(void *opaque)
memset(s->batch_notify_vqs, 0, sizeof(bitmap));
for (j = 0; j < nvqs; j += BITS_PER_LONG) {
- unsigned long bits = bitmap[j];
+ unsigned long bits = bitmap[j / BITS_PER_LONG];
while (bits != 0) {
unsigned i = j + ctzl(bits);
--
2.23.0