r21505: make sure mlock()'d memory is aligned on a page boundary

2 files changed, 26 insertions, 7 deletions

diff --git a/source/nsswitch/winbindd_cred_cache.c b/source/nsswitch/winbindd_cred_cache.c
index 50d39dd670b..8dc8fab4ac1 100644
--- a/source/nsswitch/winbindd_cred_cache.c
+++ b/source/nsswitch/winbindd_cred_cache.c
@@ -471,6 +471,8 @@ static NTSTATUS store_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp, const
 #if !defined(HAVE_MLOCK)
 	return NT_STATUS_OK;
 #else
+	int psize = getpagesize();
+
 	/* new_entry->nt_hash is the base pointer for the block
 	   of memory pointed into by new_entry->lm_hash and
 	   new_entry->pass (if we're storing plaintext). */
@@ -480,17 +482,29 @@ static NTSTATUS store_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp, const
 		memcredp->len += strlen(pass)+1;
 	}
 
-	memcredp->nt_hash = (unsigned char *)TALLOC_ZERO(memcredp, memcredp->len);
-	if (!memcredp->nt_hash) {
+	/* On non-linux platforms, mlock()'d memory must be aligned on
+	   a page boundary so allocate a bit more so we can offset
+	   enough */
+
+	memcredp->len += psize;
+			  
+	memcredp->buffer = (unsigned char*)TALLOC_ZERO(memcredp, memcredp->len);
+				  
+	if (!memcredp->buffer) {
 		return NT_STATUS_NO_MEMORY;
 	}
+				  
+
+	/* point the nt_hash at the page boundary in the buffer */
 
+	memcredp->nt_hash = memcredp->buffer +
+		(psize - ((uint32)memcredp->buffer % psize));
 	memcredp->lm_hash = memcredp->nt_hash + NT_HASH_LEN;
+
 #ifdef DEBUG_PASSWORD
 	DEBUG(10,("mlocking memory: %p\n", memcredp->nt_hash));
 #endif		
-
-	if ((mlock(memcredp->nt_hash, memcredp->len)) == -1) {
+	if ((mlock(memcredp->nt_hash, memcredp->len-psize)) == -1) {
 		DEBUG(0,("failed to mlock memory: %s (%d)\n", 
 			strerror(errno), errno));
 		return map_nt_error_from_unix(errno);
@@ -522,13 +536,16 @@ static NTSTATUS delete_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp)
 #if !defined(HAVE_MUNLOCK)
 	return NT_STATUS_OK;
 #else
-	if (munlock(memcredp->nt_hash, memcredp->len) == -1) {
+	int psize = getpagesize();	
+
+	if (munlock(memcredp->buffer, memcredp->len - psize) == -1) {
 		DEBUG(0,("failed to munlock memory: %s (%d)\n", 
 			strerror(errno), errno));
 		return map_nt_error_from_unix(errno);
 	}
-	memset(memcredp->nt_hash, '\0', memcredp->len);
-	TALLOC_FREE(memcredp->nt_hash);
+	memset(memcredp->buffer, '\0', memcredp->len);
+	TALLOC_FREE(memcredp->buffer);
+	memcredp->nt_hash = NULL;
 	memcredp->lm_hash = NULL;
 	memcredp->pass = NULL;
 	memcredp->len = 0;
diff --git a/source/nsswitch/winbindd_nss.h b/source/nsswitch/winbindd_nss.h
index b6c262e4667..919575d9576 100644
--- a/source/nsswitch/winbindd_nss.h
+++ b/source/nsswitch/winbindd_nss.h
@@ -469,6 +469,8 @@ struct WINBINDD_MEMORY_CREDS {
 	uid_t uid;
 	int ref_count;
 	size_t len;
+	unsigned char *buffer;  /* buffer block containing the
+				   following 3 */
 	unsigned char *nt_hash; /* Base pointer for the following 2 */
 	unsigned char *lm_hash;
 	char *pass;