Using a structure for a tdb key can lead to insideous, hard

to find bugs. On 64 bit IRIX, structure packing means that
a
struct {
SMB_DEV_T dev /* 4 bytes */
SMB_INO_T ino /* 8 bytes */
}

has 4 bytes of padding between the two members. If you
don't null the memory before using it as a tdb key,
you randomly can't find keys depending on what is in
the padding. This caused me immense pain and was hard
to track down.... :-)

Jeremy.
(This used to be commit f2a5ba3f0939f59097f0ef6a25f1cf9b5574f157)

1 files changed, 2 insertions, 0 deletions

diff --git a/source3/locking/posix.c b/source3/locking/posix.c
index 0ab46f9ca4..d1edb1ef57 100644
--- a/source3/locking/posix.c
+++ b/source3/locking/posix.c
@@ -73,6 +73,8 @@ static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
 {
 	static struct posix_lock_key key;
 	TDB_DATA kbuf;
+
+	memset(&key, '\0', sizeof(key));
 	key.device = dev;
 	key.inode = inode;
 	kbuf.dptr = (char *)&key;