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[Qemu-devel] [PATCH v2] virtio: add check for descriptor's mapped addres
From: |
P J P |
Subject: |
[Qemu-devel] [PATCH v2] virtio: add check for descriptor's mapped address |
Date: |
Mon, 19 Sep 2016 14:36:11 +0530 |
From: Prasad J Pandit <address@hidden>
virtio back end uses set of buffers to facilitate I/O operations.
If its size is too large, 'cpu_physical_memory_map' could return
a null address. This would result in a null dereference while
un-mapping descriptors. Add check to avoid it.
Reported-by: Qinghao Tang <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
hw/virtio/virtio.c | 5 +++++
1 file changed, 5 insertions(+)
Update per:
-> https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg03889.html
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 15ee3a7..311dd0b 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -472,6 +472,11 @@ static void virtqueue_map_desc(unsigned int *p_num_sg,
hwaddr *addr, struct iove
}
iov[num_sg].iov_base = cpu_physical_memory_map(pa, &len, is_write);
+ if (!iov[num_sg].iov_base) {
+ error_report("virtio: bogus descriptor or out of resources");
+ exit(EXIT_FAILURE);
+ }
+
iov[num_sg].iov_len = len;
addr[num_sg] = pa;
--
2.5.5
- [Qemu-devel] [PATCH v2] virtio: add check for descriptor's mapped address,
P J P <=