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path: root/drivers/md/dm-ioctl.c
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Diffstat (limited to 'drivers/md/dm-ioctl.c')
-rw-r--r--drivers/md/dm-ioctl.c46
1 files changed, 31 insertions, 15 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 6d12775a1061..4cacdad2270a 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1501,14 +1501,10 @@ static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
return r;
}
-static void free_params(struct dm_ioctl *param)
-{
- vfree(param);
-}
-
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;
@@ -1516,17 +1512,30 @@ 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)) {
- vfree(dmi);
- return -EFAULT;
}
+ 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;
}
static int validate_params(uint cmd, struct dm_ioctl *param)
@@ -1534,6 +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 ||
@@ -1561,10 +1571,11 @@ 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;
- size_t param_size;
+ size_t input_param_size;
/* only root can play with this */
if (!capable(CAP_SYS_ADMIN))
@@ -1611,13 +1622,15 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
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;
- param_size = param->data_size;
param->data_size = sizeof(*param);
- r = fn(param, param_size);
+ r = fn(param, input_param_size);
/*
* Copy the results back to userland.
@@ -1625,8 +1638,11 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
if (!r && copy_to_user(user, param, param->data_size))
r = -EFAULT;
- out:
- free_params(param);
+out:
+ if (wipe_buffer)
+ memset(param, 0, input_param_size);
+
+ vfree(param);
return r;
}