bgpd: fix cleanup of dampening configuration

The bgp_damp_config_clean() function was deallocating some arrays without
resetting the variables that represent their sizes. This was leading to
some crashes because other parts of the code iterate over these arrays
by looking at their corresponding sizes, which could be invalid.

Fixes the following segfaults (which only happen under certain
circumstances):
vtysh -c "configure terminal" -c "router bgp 1" -c "bgp dampening"
vtysh -c "configure terminal" -c "router bgp 1" -c "no bgp dampening"
vtysh -c "configure terminal" -c "router bgp 1" -c "no bgp dampening 45"
vtysh -c "" -c "clear ip bgp dampening"

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

diff --git a/bgpd/bgp_damp.c b/bgpd/bgp_damp.c
index cff5caf52fed82f6d86815ddf767d006158f0508..86cee39a621cd9839de6a8ae766f0a03d954beb1 100644 (file)
--- a/bgpd/bgp_damp.c
+++ b/bgpd/bgp_damp.c
@@ -448,12 +448,15 @@ static void bgp_damp_config_clean(struct bgp_damp_config *damp)
 {
        /* Free decay array */
        XFREE(MTYPE_BGP_DAMP_ARRAY, damp->decay_array);
+       damp->decay_array_size = 0;
 
        /* Free reuse index array */
        XFREE(MTYPE_BGP_DAMP_ARRAY, damp->reuse_index);
+       damp->reuse_index_size = 0;
 
        /* Free reuse list array. */
        XFREE(MTYPE_BGP_DAMP_ARRAY, damp->reuse_list);
+       damp->reuse_list_size = 0;
 }
 
 /* Clean all the bgp_damp_info stored in reuse_list. */