bgpd: fix memory leak in cluster_intern()

[enkechen-panw]

Fixed memory leak in cluster_intern().

[greptile-apps]

Greptile Summary

Fixed memory leak in cluster_intern() by adding cleanup logic when hash_get() returns an existing cluster entry.

• Added check to free the input cluster parameter when it differs from the returned hash entry
• Aligns cluster_intern() with the same pattern used by other intern functions (transit_intern, bgp_nhc_intern, srv6_vpn_intern)
• The leak occurred when hash_get() found an existing cluster in the hash table but the newly allocated input cluster was not freed

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The fix correctly addresses a memory leak by following the established pattern used in other similar functions throughout the codebase. The change is minimal, well-contained, and logically sound.
• No files require special attention

Important Files Changed

Filename	Overview
bgpd/bgp_attr.c	Fixed memory leak by freeing cluster parameter when hash_get returns existing entry

_{Last reviewed commit: 255a123}

[donaldsharp]

@Mergifyio backport dev/10.6 stable/10.5 stable/10.4

[mergify]

backport dev/10.6 stable/10.5 stable/10.4

✅ Backports have been created

Details

• #20918 bgpd: fix memory leak in cluster_intern() (backport #20913) has been created for branch dev/10.6
• #20919 bgpd: fix memory leak in cluster_intern() (backport #20913) has been created for branch stable/10.5
• #20920 bgpd: fix memory leak in cluster_intern() (backport #20913) has been created for branch stable/10.4