diff options
Diffstat (limited to 'libc/nscd/nscd_helper.c')
| -rw-r--r-- | libc/nscd/nscd_helper.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/libc/nscd/nscd_helper.c b/libc/nscd/nscd_helper.c index c09f00859..fe63f9a7f 100644 --- a/libc/nscd/nscd_helper.c +++ b/libc/nscd/nscd_helper.c @@ -468,6 +468,15 @@ __nscd_get_map_ref (request_type type, const char *name, } +/* Using sizeof (hashentry) is not always correct to determine the size of + the data structure as found in the nscd cache. The program could be + a 64-bit process and nscd could be a 32-bit process. In this case + sizeof (hashentry) would overestimate the size. The following is + the minimum size of such an entry, good enough for our tests here. */ +#define MINIMUM_HASHENTRY_SIZE \ + (offsetof (struct hashentry, dellist) + sizeof (int32_t)) + + /* Don't return const struct datahead *, as eventhough the record is normally constant, it can change arbitrarily during nscd garbage collection. */ @@ -481,10 +490,11 @@ __nscd_cache_search (request_type type, const char *key, size_t keylen, ref_t trail = mapped->head->array[hash]; trail = atomic_forced_read (trail); ref_t work = trail; - size_t loop_cnt = datasize / (offsetof (struct datahead, data) + datalen); + size_t loop_cnt = datasize / (MINIMUM_HASHENTRY_SIZE + + offsetof (struct datahead, data) / 2); int tick = 0; - while (work != ENDREF && work + sizeof (struct hashentry) <= datasize) + while (work != ENDREF && work + MINIMUM_HASHENTRY_SIZE <= datasize) { struct hashentry *here = (struct hashentry *) (mapped->data + work); ref_t here_key, here_packet; @@ -541,7 +551,7 @@ __nscd_cache_search (request_type type, const char *key, size_t keylen, return NULL; #endif - if (trail + sizeof (struct hashentry) > datasize) + if (trail + MINIMUM_HASHENTRY_SIZE > datasize) return NULL; trail = atomic_forced_read (trailelem->next); |