39 lines
1.1 KiB
Diff
39 lines
1.1 KiB
Diff
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From: Prasad J Pandit <address@hidden>
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virtio back end uses set of buffers to facilitate I/O operations.
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If its size is too large, 'cpu_physical_memory_map' could return
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a null address. This would result in a null dereference
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while un-mapping descriptors. Add check to avoid it.
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Reported-by: Qinghao Tang <address@hidden>
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Signed-off-by: Prasad J Pandit <address@hidden>
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---
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hw/virtio/virtio.c | 10 ++++++----
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1 file changed, 6 insertions(+), 4 deletions(-)
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diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
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index 15ee3a7..0a4c5b6 100644
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--- a/hw/virtio/virtio.c
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+++ b/hw/virtio/virtio.c
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@@ -472,12 +472,14 @@ static void virtqueue_map_desc(unsigned int *p_num_sg, hwaddr *addr, struct iove
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}
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iov[num_sg].iov_base = cpu_physical_memory_map(pa, &len, is_write);
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- iov[num_sg].iov_len = len;
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- addr[num_sg] = pa;
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+ if (iov[num_sg].iov_base) {
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+ iov[num_sg].iov_len = len;
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+ addr[num_sg] = pa;
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+ pa += len;
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+ num_sg++;
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+ }
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sz -= len;
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- pa += len;
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- num_sg++;
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}
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*p_num_sg = num_sg;
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}
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--
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2.5.5
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