---

yaml
---
r: 242563
b: refs/heads/master
c: f868120
h: refs/heads/master
i:
  242561: cc6bbfc
  242559: c88e064
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6bb43b5d1f54fb44c0408d86d5e71e4405a3ebe1
+refs/heads/master: f868120549fc1664b2c451d4b9882a363928c698

trunk/drivers/md/dm-ioctl.c

@@ -1504,24 +1504,36 @@ static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
 {
 	struct dm_ioctl tmp, *dmi;
+	int secure_data;
 
 	if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
 		return -EFAULT;
 
 	if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
 		return -EINVAL;
 
+	secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
+
 	dmi = vmalloc(tmp.data_size);
-	if (!dmi)
+	if (!dmi) {
+		if (secure_data && clear_user(user, tmp.data_size))
+			return -EFAULT;
 		return -ENOMEM;
+	}
 
 	if (copy_from_user(dmi, user, tmp.data_size))
 		goto bad;
 
+	/* Wipe the user buffer so we do not return it to userspace */
+	if (secure_data && clear_user(user, tmp.data_size))
+		goto bad;
+
 	*param = dmi;
 	return 0;
 
 bad:
+	if (secure_data)
+		memset(dmi, 0, tmp.data_size);
 	vfree(dmi);
 	return -EFAULT;
 }
@@ -1531,6 +1543,7 @@ static int validate_params(uint cmd, struct dm_ioctl *param)
 	/* Always clear this flag */
 	param->flags &= ~DM_BUFFER_FULL_FLAG;
 	param->flags &= ~DM_UEVENT_GENERATED_FLAG;
+	param->flags &= ~DM_SECURE_DATA_FLAG;
 
 	/* Ignores parameters */
 	if (cmd == DM_REMOVE_ALL_CMD ||
@@ -1558,6 +1571,7 @@ static int validate_params(uint cmd, struct dm_ioctl *param)
 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
 {
 	int r = 0;
+	int wipe_buffer;
 	unsigned int cmd;
 	struct dm_ioctl *uninitialized_var(param);
 	ioctl_fn fn = NULL;
@@ -1602,13 +1616,15 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
 	 * Copy the parameters into kernel space.
 	 */
 	r = copy_params(user, &param);
-	input_param_size = param->data_size;
 
 	current->flags &= ~PF_MEMALLOC;
 
 	if (r)
 		return r;
 
+	input_param_size = param->data_size;
+	wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;
+
 	r = validate_params(cmd, param);
 	if (r)
 		goto out;
@@ -1623,6 +1639,9 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
 		r = -EFAULT;
 
 out:
+	if (wipe_buffer)
+		memset(param, 0, input_param_size);
+
 	vfree(param);
 	return r;
 }

trunk/include/linux/dm-ioctl.h

@@ -267,9 +267,9 @@ enum {
 #define DM_DEV_SET_GEOMETRY	_IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 
 #define DM_VERSION_MAJOR	4
-#define DM_VERSION_MINOR	19
-#define DM_VERSION_PATCHLEVEL	1
-#define DM_VERSION_EXTRA	"-ioctl (2011-01-07)"
+#define DM_VERSION_MINOR	20
+#define DM_VERSION_PATCHLEVEL	0
+#define DM_VERSION_EXTRA	"-ioctl (2011-02-02)"
 
 /* Status bits */
 #define DM_READONLY_FLAG	(1 << 0) /* In/Out */
@@ -328,4 +328,10 @@ enum {
  */
 #define DM_UUID_FLAG			(1 << 14) /* In */
 
+/*
+ * If set, all buffers are wiped after use. Use when sending
+ * or requesting sensitive data such as an encryption key.
+ */
+#define DM_SECURE_DATA_FLAG		(1 << 15) /* In */
+
 #endif				/* _LINUX_DM_IOCTL_H */