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-rw-r--r--drivers/md/dm-ioctl.c23
-rw-r--r--include/linux/dm-ioctl.h12
2 files changed, 30 insertions, 5 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 3a8f6a0..4cacdad 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1504,6 +1504,7 @@ 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;
@@ -1511,17 +1512,28 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
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;
}
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 78bbf47..3708455 100644
--- a/include/linux/dm-ioctl.h
+++ b/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 */