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authorLennart Poettering <lennart@poettering.net>2014-07-18 21:01:22 +0200
committerLennart Poettering <lennart@poettering.net>2014-07-18 21:01:40 +0200
commitcbd4560ea2c9f0ae77df1fc64685ff4e559810b6 (patch)
tree2985c94ac0caaed4a10aea5d532fb3917d82fa31
parent878cd63db2d6cfc00ae4d68355a2d5402cd9f24f (diff)
resolved: various bad memory access fixes to the cache
-rw-r--r--src/resolve/resolved-dns-cache.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c
index 7093b5a357..ce74a81f6a 100644
--- a/src/resolve/resolved-dns-cache.c
+++ b/src/resolve/resolved-dns-cache.c
@@ -21,7 +21,10 @@
#include "resolved-dns-cache.h"
+/* Never cache more than 1K entries */
#define CACHE_MAX 1024
+
+/* We never keep any item longer than 10min in our cache */
#define CACHE_TTL_MAX_USEC (10 * USEC_PER_MINUTE)
static void dns_cache_item_free(DnsCacheItem *i) {
@@ -79,7 +82,7 @@ void dns_cache_remove(DnsCache *c, DnsResourceKey *key) {
assert(c);
assert(key);
- while ((i = hashmap_get(c->rrsets, &key)))
+ while ((i = hashmap_get(c->rrsets, key)))
dns_cache_item_remove_and_free(c, i);
}
@@ -105,6 +108,10 @@ static void dns_cache_make_space(DnsCache *c, unsigned add) {
break;
i = prioq_peek(c->expire);
+ assert(i);
+
+ /* Take an extra reference to the RR so that the key
+ * doesn't go away in the middle of the remove call */
rr = dns_resource_record_ref(i->rr);
dns_cache_remove(c, &rr->key);
}
@@ -118,6 +125,7 @@ void dns_cache_prune(DnsCache *c) {
/* Remove all entries that are past their TTL */
for (;;) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
DnsCacheItem *i;
usec_t ttl;
@@ -135,7 +143,10 @@ void dns_cache_prune(DnsCache *c) {
if (i->timestamp + ttl > t)
break;
- dns_cache_remove(c, &i->rr->key);
+ /* Take an extra reference to the RR so that the key
+ * doesn't go away in the middle of the remove call */
+ rr = dns_resource_record_ref(i->rr);
+ dns_cache_remove(c, &rr->key);
}
}
@@ -165,11 +176,11 @@ static void dns_cache_item_update(DnsCache *c, DnsCacheItem *i, DnsResourceRecor
assert_se(hashmap_replace(c->rrsets, &rr->key, i) >= 0);
}
+ dns_resource_record_ref(rr);
dns_resource_record_unref(i->rr);
- i->rr = dns_resource_record_ref(rr);
+ i->rr = rr;
i->timestamp = timestamp;
-
prioq_reshuffle(c->expire, i, &i->expire_prioq_idx);
}