From 3a2feed81419853e1288bd63b7887363a0c267b7 Mon Sep 17 00:00:00 2001 From: Jeremy Harris Date: Sun, 8 Sep 2019 14:41:48 +0100 Subject: [PATCH 1/1] Fix unaligned access (more cleanly) in DNS regative-caching --- src/src/dns.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/src/src/dns.c b/src/src/dns.c index 04cb046f4..44654353c 100644 --- a/src/src/dns.c +++ b/src/src/dns.c @@ -616,14 +616,10 @@ Arguments: Returns: the return code */ -/*XXX the derivation of this value needs explaining */ +/* we need: 255 +1 + (max(typetext) == 5) +1 + max(chars_for_long-max) +1 */ #define DNS_FAILTAG_MAX 290 -#define alignment \ - (sizeof(void *) > sizeof(double) ? sizeof(void *) : sizeof(double)) -#define align(n) \ - (((((intptr_t)n) + (alignment-1)) / alignment) * alignment) #define DNS_FAILNODE_SIZE \ - align(sizeof(tree_node) + DNS_FAILTAG_MAX + sizeof(expiring_data)) + (sizeof(expiring_data) + sizeof(tree_node) + DNS_FAILTAG_MAX) static int dns_fail_return(const uschar * name, int type, time_t expiry, int rc) @@ -637,10 +633,9 @@ if ((previous = tree_search(tree_dns_fails, node_name))) e = previous->data.ptr; else { - new = store_get_perm(DNS_FAILNODE_SIZE, is_tainted(name)); - + e = store_get_perm(DNS_FAILNODE_SIZE, is_tainted(name)); + new = (void *)(e+1); dns_fail_tag(new->name, name, type); - e = (expiring_data *) align((char *)new + sizeof(tree_node) + DNS_FAILTAG_MAX); new->data.ptr = e; (void)tree_insertnode(&tree_dns_fails, new); } -- 2.30.2