Upstream fix ac888d5886 ("net: do not delay dst_entries_add() in
dst_release()") moved decrementing the dst count from dst_destroy to
dst_release to avoid accessing already freed data in case of netns
dismantle. However in case CONFIG_DST_CACHE is enabled and OvS+tunnels
are used, this fix is incomplete as the same issue will be seen for
cached dsts:
Unable to handle kernel paging request at virtual address ffff5aabf6b5c000
Call trace:
percpu_counter_add_batch+0x3c/0x160 (P)
dst_release+0xec/0x108
dst_cache_destroy+0x68/0xd8
dst_destroy+0x13c/0x168
dst_destroy_rcu+0x1c/0xb0
rcu_do_batch+0x18c/0x7d0
rcu_core+0x174/0x378
rcu_core_si+0x18/0x30
Fix this by invalidating the cache, and thus decrementing cached dst
counters, in dst_release too.
Fixes: d71785ffc7 ("net: add dst_cache to ovs vxlan lwtunnel")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Link: https://patch.msgid.link/20250326173634.31096-1-atenart@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
3a0a3ff659