diff options
Diffstat (limited to 'drivers/md/dm-ioctl.c')
| -rw-r--r-- | drivers/md/dm-ioctl.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 3a8f6a0e6eb..4cacdad2270 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, ¶m); - 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; } |