[ Upstream commit 2abe05234f2e892728c388169631e4b99f354c86 ] Creation and management of L2TPv3 tunnels and session through netlink requires CAP_NET_ADMIN. However, a process with CAP_NET_ADMIN in a non-initial user namespace gets an EPERM due to the use of the genetlink GENL_ADMIN_PERM flag. Thus, management of L2TP VPNs inside an unprivileged container won't work. We replaced the GENL_ADMIN_PERM by the GENL_UNS_ADMIN_PERM flag similar to other network modules which also had this problem, e.g., openvswitch (commit 4a92602aa1cd "openvswitch: allow management from inside user namespaces") and nl80211 (commit 5617c6cd6f844 "nl80211: Allow privileged operations from user namespaces"). I tested this in the container runtime trustm3 (trustm3.github.io) and was able to create l2tp tunnels and sessions in unpriviliged (user namespaced) containers using a private network namespace. For other runtimes such as docker or lxc this should work, too. Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.
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