Permalink
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Browse files
Browse the repository at this point in the history
virtio-net: fix use after unmap/free for sg
When mergeable buffer is enabled, we try to set the num_buffers after the virtqueue elem has been unmapped. This will lead several issues, E.g a use after free when the descriptor has an address which belongs to the non direct access region. In this case we use bounce buffer that is allocated during address_space_map() and freed during address_space_unmap(). Fixing this by storing the elems temporarily in an array and delay the unmap after we set the the num_buffers. This addresses CVE-2021-3748. Reported-by: Alexander Bulekov <alxndr@bu.edu> Fixes: fbe78f4 ("virtio-net support") Cc: qemu-stable@nongnu.org Signed-off-by: Jason Wang <jasowang@redhat.com>
- Loading branch information
Showing
1 changed file
with
32 additions
and
7 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters