mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-05 12:16:29 -04:00
a3bd2102e4
Commit40867d74c3("net: Add l3mdev index to flow struct and avoid oif reset for port devices") adds a new entry (flowi_l3mdev) in the common flow struct used for indicating the l3mdev index for later rule and table matching. The l3mdev_update_flow() has been adapted to properly set the flowi_l3mdev based on the flowi_oif/flowi_iif. In fact, when a valid flowi_iif is supplied to the l3mdev_update_flow(), this function can update the flowi_l3mdev entry only if it has not yet been set (i.e., the flowi_l3mdev entry is equal to 0). The SRv6 End.DT6 behavior in VRF mode leverages a VRF device in order to force the routing lookup into the associated routing table. This routing operation is performed by seg6_lookup_any_nextop() preparing a flowi6 data structure used by ip6_route_input_lookup() which, in turn, (indirectly) invokes l3mdev_update_flow(). However, seg6_lookup_any_nexthop() does not initialize the new flowi_l3mdev entry which is filled with random garbage data. This prevents l3mdev_update_flow() from properly updating the flowi_l3mdev with the VRF index, and thus SRv6 End.DT6 (VRF mode)/DT46 behaviors are broken. This patch correctly initializes the flowi6 instance allocated and used by seg6_lookup_any_nexhtop(). Specifically, the entire flowi6 instance is wiped out: in case new entries are added to flowi/flowi6 (as happened with the flowi_l3mdev entry), we should no longer have incorrectly initialized values. As a result of this operation, the value of flowi_l3mdev is also set to 0. The proposed fix can be tested easily. Starting from the commit referenced in the Fixes, selftests [1],[2] indicate that the SRv6 End.DT6 (VRF mode)/DT46 behaviors no longer work correctly. By applying this patch, those behaviors are back to work properly again. [1] - tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh [2] - tools/testing/selftests/net/srv6_end_dt6_l3vpn_test.sh Fixes:40867d74c3("net: Add l3mdev index to flow struct and avoid oif reset for port devices") Reported-by: Anton Makarov <am@3a-alliance.com> Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20220608091917.20345-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@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.