diff --git a/sys/netproto/smb/smb_crypt.c b/sys/netproto/smb/smb_crypt.c
--- a/sys/netproto/smb/smb_crypt.c
+++ b/sys/netproto/smb/smb_crypt.c
@@ -84,6 +84,8 @@
 	ksp = kmalloc(sizeof(des_key_schedule), M_SMBTEMP, M_WAITOK);
 	des_set_key((des_cblock *)kk, *ksp);
 	des_ecb_encrypt((des_cblock *)data, (des_cblock *)dest, *ksp, 1);
+	explicit_bzero(kk, sizeof(kk));
+	explicit_bzero(*ksp, sizeof(*ksp));
 	kfree(ksp, M_SMBTEMP);
 }