2e9fd2d0f6
[ Upstream commit cfc56f85e72f5b9c5c5be26dc2b16518d36a7868 ]
When uncloning an skb dst and its associated metadata a new dst+metadata
is allocated and the tunnel information from the old metadata is copied
over there.
The issue is the tunnel metadata has references to cached dst, which are
copied along the way. When a dst+metadata refcount drops to 0 the
metadata is freed including the cached dst entries. As they are also
referenced in the initial dst+metadata, this ends up in UaFs.
In practice the above did not happen because of another issue, the
dst+metadata was never freed because its refcount never dropped to 0
(this will be fixed in a subsequent patch).
Fix this by initializing the dst cache after copying the tunnel
information from the old metadata to also unshare the dst cache.
Fixes: d71785ffc7e7 ("net: add dst_cache to ovs vxlan lwtunnel")
Cc: Paolo Abeni <pabeni@redhat.com>
Reported-by: Vlad Buslov <vladbu@nvidia.com>
Tested-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.