commit bc8f194c8c29e46e8ee4034f06e46988dfff38f7 Author: Siddhesh Poyarekar Date: Wed Apr 30 12:00:39 2014 +0530 Initialize all of datahead structure in nscd (BZ #16791) The datahead structure has an unused padding field that remains uninitialized. Valgrind prints out a warning for it on querying a netgroups entry. This is harmless, but is a potential data leak since it would result in writing out an uninitialized byte to the cache file. Besides, this happens only when there is a cache miss, so we're not adding computation to any fast path. commit 1cdeb2372ddecac0dfe0c132a033e9590ffa07d2 Author: Siddhesh Poyarekar Date: Wed Apr 30 11:57:09 2014 +0530 Consolidate code to initialize nscd dataset header This patch consolidates the code to initialize the header of a dataset into a single set of functions (one for positive and another for negative datasets) primarily to reduce repetition of code. The secondary reason is to simplify Patch 2/2 which fixes the problem of an uninitialized byte in the header by initializing an unused field in the structure and hence preventing a possible data leak into the cache file. diff --git glibc-2.17-c758a686/nscd/aicache.c glibc-2.17-c758a686/nscd/aicache.c index 98d40a1..d7966bd 100644 --- glibc-2.17-c758a686/nscd/aicache.c +++ glibc-2.17-c758a686/nscd/aicache.c @@ -383,17 +383,12 @@ addhstaiX (struct database_dyn *db, int fd, request_header *req, cp = family; } - /* Fill in the rest of the dataset. */ - dataset->head.allocsize = total + req->key_len; - dataset->head.recsize = total - offsetof (struct dataset, resp); - dataset->head.notfound = false; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - - /* Compute the timeout time. */ - dataset->head.ttl = ttl == INT32_MAX ? db->postimeout : ttl; - timeout = dataset->head.timeout = time (NULL) + dataset->head.ttl; + timeout = datahead_init_pos (&dataset->head, total + req->key_len, + total - offsetof (struct dataset, resp), + he == NULL ? 0 : dh->nreloads + 1, + ttl == INT32_MAX ? db->postimeout : ttl); + /* Fill in the rest of the dataset. */ dataset->resp.version = NSCD_VERSION; dataset->resp.found = 1; dataset->resp.naddrs = naddrs; @@ -528,15 +523,9 @@ next_nip: else if ((dataset = mempool_alloc (db, (sizeof (struct dataset) + req->key_len), 1)) != NULL) { - dataset->head.allocsize = sizeof (struct dataset) + req->key_len; - dataset->head.recsize = total; - dataset->head.notfound = true; - dataset->head.nreloads = 0; - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = time (NULL) + db->negtimeout; - dataset->head.ttl = db->negtimeout; + timeout = datahead_init_neg (&dataset->head, + sizeof (struct dataset) + req->key_len, + total, db->negtimeout); /* This is the reply. */ memcpy (&dataset->resp, ¬found, total); diff --git glibc-2.17-c758a686/nscd/grpcache.c glibc-2.17-c758a686/nscd/grpcache.c index b5a33eb..df59fa7 100644 --- glibc-2.17-c758a686/nscd/grpcache.c +++ glibc-2.17-c758a686/nscd/grpcache.c @@ -128,14 +128,10 @@ cache_addgr (struct database_dyn *db, int fd, request_header *req, } else if ((dataset = mempool_alloc (db, sizeof (struct dataset) + req->key_len, 1)) != NULL) { - dataset->head.allocsize = sizeof (struct dataset) + req->key_len; - dataset->head.recsize = total; - dataset->head.notfound = true; - dataset->head.nreloads = 0; - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = t + db->negtimeout; + timeout = datahead_init_neg (&dataset->head, + (sizeof (struct dataset) + + req->key_len), total, + db->negtimeout); /* This is the reply. */ memcpy (&dataset->resp, ¬found, total); @@ -232,14 +228,10 @@ cache_addgr (struct database_dyn *db, int fd, request_header *req, dataset_temporary = true; } - dataset->head.allocsize = total + n; - dataset->head.recsize = total - offsetof (struct dataset, resp); - dataset->head.notfound = false; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = t + db->postimeout; + timeout = datahead_init_pos (&dataset->head, total + n, + total - offsetof (struct dataset, resp), + he == NULL ? 0 : dh->nreloads + 1, + db->postimeout); dataset->resp.version = NSCD_VERSION; dataset->resp.found = 1; diff --git glibc-2.17-c758a686/nscd/hstcache.c glibc-2.17-c758a686/nscd/hstcache.c index a79b67a..d4f1ad2 100644 --- glibc-2.17-c758a686/nscd/hstcache.c +++ glibc-2.17-c758a686/nscd/hstcache.c @@ -152,15 +152,11 @@ cache_addhst (struct database_dyn *db, int fd, request_header *req, else if ((dataset = mempool_alloc (db, (sizeof (struct dataset) + req->key_len), 1)) != NULL) { - dataset->head.allocsize = sizeof (struct dataset) + req->key_len; - dataset->head.recsize = total; - dataset->head.notfound = true; - dataset->head.nreloads = 0; - dataset->head.usable = true; - - /* Compute the timeout time. */ - dataset->head.ttl = ttl == INT32_MAX ? db->negtimeout : ttl; - timeout = dataset->head.timeout = t + dataset->head.ttl; + timeout = datahead_init_neg (&dataset->head, + (sizeof (struct dataset) + + req->key_len), total, + (ttl == INT32_MAX + ? db->negtimeout : ttl)); /* This is the reply. */ memcpy (&dataset->resp, resp, total); @@ -257,15 +253,10 @@ cache_addhst (struct database_dyn *db, int fd, request_header *req, alloca_used = true; } - dataset->head.allocsize = total + req->key_len; - dataset->head.recsize = total - offsetof (struct dataset, resp); - dataset->head.notfound = false; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - - /* Compute the timeout time. */ - dataset->head.ttl = ttl == INT32_MAX ? db->postimeout : ttl; - timeout = dataset->head.timeout = t + dataset->head.ttl; + timeout = datahead_init_pos (&dataset->head, total + req->key_len, + total - offsetof (struct dataset, resp), + he == NULL ? 0 : dh->nreloads + 1, + ttl == INT32_MAX ? db->postimeout : ttl); dataset->resp.version = NSCD_VERSION; dataset->resp.found = 1; diff --git glibc-2.17-c758a686/nscd/initgrcache.c glibc-2.17-c758a686/nscd/initgrcache.c index 1bf9f0d..361319f 100644 --- glibc-2.17-c758a686/nscd/initgrcache.c +++ glibc-2.17-c758a686/nscd/initgrcache.c @@ -213,14 +213,10 @@ addinitgroupsX (struct database_dyn *db, int fd, request_header *req, else if ((dataset = mempool_alloc (db, (sizeof (struct dataset) + req->key_len), 1)) != NULL) { - dataset->head.allocsize = sizeof (struct dataset) + req->key_len; - dataset->head.recsize = total; - dataset->head.notfound = true; - dataset->head.nreloads = 0; - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = time (NULL) + db->negtimeout; + timeout = datahead_init_neg (&dataset->head, + (sizeof (struct dataset) + + req->key_len), total, + db->negtimeout); /* This is the reply. */ memcpy (&dataset->resp, ¬found, total); @@ -276,14 +272,10 @@ addinitgroupsX (struct database_dyn *db, int fd, request_header *req, alloca_used = true; } - dataset->head.allocsize = total + req->key_len; - dataset->head.recsize = total - offsetof (struct dataset, resp); - dataset->head.notfound = false; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = time (NULL) + db->postimeout; + timeout = datahead_init_pos (&dataset->head, total + req->key_len, + total - offsetof (struct dataset, resp), + he == NULL ? 0 : dh->nreloads + 1, + db->postimeout); dataset->resp.version = NSCD_VERSION; dataset->resp.found = 1; diff --git glibc-2.17-c758a686/nscd/netgroupcache.c glibc-2.17-c758a686/nscd/netgroupcache.c index 820d823..b3d40e9 100644 --- glibc-2.17-c758a686/nscd/netgroupcache.c +++ glibc-2.17-c758a686/nscd/netgroupcache.c @@ -90,15 +90,9 @@ do_notfound (struct database_dyn *db, int fd, request_header *req, /* If we cannot permanently store the result, so be it. */ if (dataset != NULL) { - dataset->head.allocsize = sizeof (struct dataset) + req->key_len; - dataset->head.recsize = total; - dataset->head.notfound = true; - dataset->head.nreloads = 0; - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = time (NULL) + db->negtimeout; - dataset->head.ttl = db->negtimeout; + timeout = datahead_init_neg (&dataset->head, + sizeof (struct dataset) + req->key_len, + total, db->negtimeout); /* This is the reply. */ memcpy (&dataset->resp, ¬found, total); @@ -359,13 +353,10 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req, /* Fill in the dataset. */ dataset = (struct dataset *) buffer; - dataset->head.allocsize = total + req->key_len; - dataset->head.recsize = total - offsetof (struct dataset, resp); - dataset->head.notfound = false; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - dataset->head.ttl = db->postimeout; - timeout = dataset->head.timeout = time (NULL) + dataset->head.ttl; + timeout = datahead_init_pos (&dataset->head, total + req->key_len, + total - offsetof (struct dataset, resp), + he == NULL ? 0 : dh->nreloads + 1, + db->postimeout); dataset->resp.version = NSCD_VERSION; dataset->resp.found = 1; @@ -541,12 +532,12 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req, dataset = &dataset_mem; } - dataset->head.allocsize = sizeof (*dataset) + req->key_len; - dataset->head.recsize = sizeof (innetgroup_response_header); + datahead_init_pos (&dataset->head, sizeof (*dataset) + req->key_len, + sizeof (innetgroup_response_header), + he == NULL ? 0 : dh->nreloads + 1, result->head.ttl); + /* Set the notfound status and timeout based on the result from + getnetgrent. */ dataset->head.notfound = result->head.notfound; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - dataset->head.ttl = result->head.ttl; dataset->head.timeout = timeout; dataset->resp.version = NSCD_VERSION; diff --git glibc-2.17-c758a686/nscd/nscd-client.h glibc-2.17-c758a686/nscd/nscd-client.h index 98f77e7..ee16df6 100644 --- glibc-2.17-c758a686/nscd/nscd-client.h +++ glibc-2.17-c758a686/nscd/nscd-client.h @@ -236,6 +236,48 @@ struct datahead } data[0]; }; +static inline time_t +datahead_init_common (struct datahead *head, nscd_ssize_t allocsize, + nscd_ssize_t recsize, uint32_t ttl) +{ + /* Initialize so that we don't write out junk in uninitialized data to the + cache. */ + memset (head, 0, sizeof (*head)); + + head->allocsize = allocsize; + head->recsize = recsize; + head->usable = true; + + head->ttl = ttl; + + /* Compute and return the timeout time. */ + return head->timeout = time (NULL) + ttl; +} + +static inline time_t +datahead_init_pos (struct datahead *head, nscd_ssize_t allocsize, + nscd_ssize_t recsize, uint8_t nreloads, uint32_t ttl) +{ + time_t ret = datahead_init_common (head, allocsize, recsize, ttl); + + head->notfound = false; + head->nreloads = nreloads; + + return ret; +} + +static inline time_t +datahead_init_neg (struct datahead *head, nscd_ssize_t allocsize, + nscd_ssize_t recsize, uint32_t ttl) +{ + time_t ret = datahead_init_common (head, allocsize, recsize, ttl); + + /* We don't need to touch nreloads here since it is set to our desired value + (0) when we clear the structure. */ + head->notfound = true; + + return ret; +} /* Structure for one hash table entry. */ struct hashentry diff --git glibc-2.17-c758a686/nscd/pwdcache.c glibc-2.17-c758a686/nscd/pwdcache.c index fa355c3..41c245b 100644 --- glibc-2.17-c758a686/nscd/pwdcache.c +++ glibc-2.17-c758a686/nscd/pwdcache.c @@ -135,14 +135,10 @@ cache_addpw (struct database_dyn *db, int fd, request_header *req, else if ((dataset = mempool_alloc (db, (sizeof (struct dataset) + req->key_len), 1)) != NULL) { - dataset->head.allocsize = sizeof (struct dataset) + req->key_len; - dataset->head.recsize = total; - dataset->head.notfound = true; - dataset->head.nreloads = 0; - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = t + db->negtimeout; + timeout = datahead_init_neg (&dataset->head, + (sizeof (struct dataset) + + req->key_len), total, + db->negtimeout); /* This is the reply. */ memcpy (&dataset->resp, ¬found, total); @@ -215,14 +211,10 @@ cache_addpw (struct database_dyn *db, int fd, request_header *req, alloca_used = true; } - dataset->head.allocsize = total + n; - dataset->head.recsize = total - offsetof (struct dataset, resp); - dataset->head.notfound = false; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = t + db->postimeout; + timeout = datahead_init_pos (&dataset->head, total + n, + total - offsetof (struct dataset, resp), + he == NULL ? 0 : dh->nreloads + 1, + db->postimeout); dataset->resp.version = NSCD_VERSION; dataset->resp.found = 1; diff --git glibc-2.17-c758a686/nscd/servicescache.c glibc-2.17-c758a686/nscd/servicescache.c index 12ce9b2..95bdcfe 100644 --- glibc-2.17-c758a686/nscd/servicescache.c +++ glibc-2.17-c758a686/nscd/servicescache.c @@ -120,14 +120,10 @@ cache_addserv (struct database_dyn *db, int fd, request_header *req, else if ((dataset = mempool_alloc (db, (sizeof (struct dataset) + req->key_len), 1)) != NULL) { - dataset->head.allocsize = sizeof (struct dataset) + req->key_len; - dataset->head.recsize = total; - dataset->head.notfound = true; - dataset->head.nreloads = 0; - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = t + db->negtimeout; + timeout = datahead_init_neg (&dataset->head, + (sizeof (struct dataset) + + req->key_len), total, + db->negtimeout); /* This is the reply. */ memcpy (&dataset->resp, ¬found, total); @@ -207,14 +203,10 @@ cache_addserv (struct database_dyn *db, int fd, request_header *req, alloca_used = true; } - dataset->head.allocsize = total + req->key_len; - dataset->head.recsize = total - offsetof (struct dataset, resp); - dataset->head.notfound = false; - dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1); - dataset->head.usable = true; - - /* Compute the timeout time. */ - timeout = dataset->head.timeout = t + db->postimeout; + timeout = datahead_init_pos (&dataset->head, total + req->key_len, + total - offsetof (struct dataset, resp), + he == NULL ? 0 : dh->nreloads + 1, + db->postimeout); dataset->resp.version = NSCD_VERSION; dataset->resp.found = 1;