bgpd: Free memory allocated by info_make() when hitting maximum-prefix

```
Direct leak of 112 byte(s) in 1 object(s) allocated from:
    0 0x7feb66337a06 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:153
    1 0x7feb660cbcc3 in qcalloc lib/memory.c:116
    2 0x55cc3cba02d1 in info_make bgpd/bgp_route.c:3831
    3 0x55cc3cbab4f1 in bgp_update bgpd/bgp_route.c:4733
    4 0x55cc3cbb0620 in bgp_nlri_parse_ip bgpd/bgp_route.c:6111
    5 0x55cc3cb79473 in bgp_update_receive bgpd/bgp_packet.c:2020
    6 0x55cc3cb7c34a in bgp_process_packet bgpd/bgp_packet.c:2929
    7 0x7feb6610ecc5 in thread_call lib/thread.c:2006
    8 0x7feb660bfb77 in frr_run lib/libfrr.c:1198
    9 0x55cc3cb17232 in main bgpd/bgp_main.c:520
    10 0x7feb65ae5082 in __libc_start_main ../csu/libc-start.c:308

SUMMARY: AddressSanitizer: 112 byte(s) leaked in 1 allocation(s).
```

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index e47a348722d0bb38d629bd552bcb01b6a5169ea2..c85de24a5cfd25e37d91c1de0b7e79e4430978b0 100644 (file)
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -4012,7 +4012,7 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
        struct attr new_attr;
        struct attr *attr_new;
        struct bgp_path_info *pi;
-       struct bgp_path_info *new;
+       struct bgp_path_info *new = NULL;
        struct bgp_path_info_extra *extra;
        const char *reason;
        char pfx_buf[BGP_PRD_PATH_STRLEN];
@@ -4806,8 +4806,6 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
        if (bgp_maximum_prefix_overflow(peer, afi, safi, 0)) {
                reason = "maximum-prefix overflow";
                bgp_attr_flush(&new_attr);
-               bgp_unlink_nexthop(new);
-               bgp_path_info_delete(dest, new);
                goto filtered;
        }
 
@@ -4882,6 +4880,13 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 /* This BGP update is filtered.  Log the reason then update BGP
    entry.  */
 filtered:
+       if (new) {
+               bgp_unlink_nexthop(new);
+               bgp_path_info_delete(dest, new);
+               bgp_path_info_extra_free(&new->extra);
+               XFREE(MTYPE_BGP_ROUTE, new);
+       }
+
        hook_call(bgp_process, bgp, afi, safi, dest, peer, true);
 
        if (bgp_debug_update(peer, p, NULL, 1)) {