676b49366a
Antoine Tenart says:
====================
net: fix issues when uncloning an skb dst+metadata
This fixes two issues when uncloning an skb dst+metadata in
tun_dst_unclone; this was initially reported by Vlad Buslov[1]. Because
of the memory leak fixed by patch 2, the issue in patch 1 never happened
in practice.
tun_dst_unclone is called from two different places, one in geneve/vxlan
to handle PMTU and one in net/openvswitch/actions.c where it is used to
retrieve tunnel information. While both Vlad and I tested the former, we
could not for the latter. I did spend quite some time trying to, but
that code path is not easy to trigger. Code inspection shows this should
be fine, the tunnel information (dst+metadata) is uncloned and the skb
it is referenced from is only consumed after all accesses to the tunnel
information are done:
do_execute_actions
output_userspace
dev_fill_metadata_dst <- dst+metadata is uncloned
ovs_dp_upcall
queue_userspace_packet
ovs_nla_put_tunnel_info <- metadata (tunnel info) is accessed
consume_skb <- dst+metadata is freed
Thanks!
Antoine
[1] https://lore.kernel.org/all/ygnhh79yluw2.fsf@nvidia.com/T/#m2f814614a4f5424cea66bbff7297f692b59b69a0
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
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