bpf, lpm: Fix check prefixlen before walking trie

When looking up an element in LPM trie, the condition 'matchlen ==
trie->max_prefixlen' will never return true, if key->prefixlen is larger
than trie->max_prefixlen. Consequently all elements in the LPM trie will
be visited and no element is returned in the end.

To resolve this, check key->prefixlen first before walking the LPM trie.

Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Signed-off-by: Florian Lehner <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

0 files changed, 0 insertions, 0 deletions