[PATCH V5 3/4] Move stack parameters for sed_ioctl to prevent oversized stack with CONFIG_KASAN

From: Scott Bauer
Date: Mon Feb 13 2017 - 11:21:09 EST


When CONFIG_KASAN is enabled, compilation fails:

block/sed-opal.c: In function 'sed_ioctl':
block/sed-opal.c:2447:1: error: the frame size of 2256 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]

Moved all the ioctl structures off the stack and dynamically activate
using _IOC_SIZE()

Fixes: 455a7b238cd6 ("block: Add Sed-opal library")

Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Scott Bauer <scott.bauer@xxxxxxxxx>
---
block/sed-opal.c | 130 +++++++++++++++++++------------------------------------
1 file changed, 45 insertions(+), 85 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 2448d4a..5733248 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -2348,7 +2348,6 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
{
void *ioctl_ptr;
int ret = -ENOTTY;
- unsigned int cmd_size = _IOC_SIZE(cmd);

if (!capable(CAP_SYS_ADMIN))
return -EACCES;
@@ -2357,94 +2356,55 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
return -ENOTSUPP;
}

- switch (cmd) {
- case IOC_OPAL_SAVE: {
- struct opal_lock_unlock lk_unlk;
-
- if (copy_from_user(&lk_unlk, arg, sizeof(lk_unlk)))
- return -EFAULT;
- return opal_save(dev, &lk_unlk);
- }
- case IOC_OPAL_LOCK_UNLOCK: {
- struct opal_lock_unlock lk_unlk;
-
- if (copy_from_user(&lk_unlk, arg, sizeof(lk_unlk)))
- return -EFAULT;
- return opal_lock_unlock(dev, &lk_unlk);
- }
- case IOC_OPAL_TAKE_OWNERSHIP: {
- struct opal_key opal_key;
-
- if (copy_from_user(&opal_key, arg, sizeof(opal_key)))
- return -EFAULT;
- return opal_take_ownership(dev, &opal_key);
- }
- case IOC_OPAL_ACTIVATE_LSP: {
- struct opal_lr_act opal_lr_act;
-
- if (copy_from_user(&opal_lr_act, arg, sizeof(opal_lr_act)))
- return -EFAULT;
- return opal_activate_lsp(dev, &opal_lr_act);
- }
- case IOC_OPAL_SET_PW: {
- struct opal_new_pw opal_pw;
-
- if (copy_from_user(&opal_pw, arg, sizeof(opal_pw)))
- return -EFAULT;
- return opal_set_new_pw(dev, &opal_pw);
- }
- case IOC_OPAL_ACTIVATE_USR: {
- struct opal_session_info session;
-
- if (copy_from_user(&session, arg, sizeof(session)))
- return -EFAULT;
- return opal_activate_user(dev, &session);
- }
- case IOC_OPAL_REVERT_TPR: {
- struct opal_key opal_key;
-
- if (copy_from_user(&opal_key, arg, sizeof(opal_key)))
- return -EFAULT;
- return opal_reverttper(dev, &opal_key);
- }
- case IOC_OPAL_LR_SETUP: {
- struct opal_user_lr_setup lrs;
-
- if (copy_from_user(&lrs, arg, sizeof(lrs)))
- return -EFAULT;
- return opal_setup_locking_range(dev, &lrs);
- }
- case IOC_OPAL_ADD_USR_TO_LR: {
- struct opal_lock_unlock lk_unlk;
-
- if (copy_from_user(&lk_unlk, arg, sizeof(lk_unlk)))
- return -EFAULT;
- return opal_add_user_to_lr(dev, &lk_unlk);
- }
- case IOC_OPAL_ENABLE_DISABLE_MBR: {
- struct opal_mbr_data mbr;
-
- if (copy_from_user(&mbr, arg, sizeof(mbr)))
- return -EFAULT;
- return opal_enable_disable_shadow_mbr(dev, &mbr);
- }
- case IOC_OPAL_ERASE_LR: {
- struct opal_session_info session;
-
- if (copy_from_user(&session, arg, sizeof(session)))
- return -EFAULT;
- return opal_erase_locking_range(dev, &session);
+ ioctl_ptr = memdup_user(arg, _IOC_SIZE(cmd));
+ if (IS_ERR_OR_NULL(ioctl_ptr)) {
+ ret = PTR_ERR(ioctl_ptr);
+ goto out;
}
- case IOC_OPAL_SECURE_ERASE_LR: {
- struct opal_session_info session;

- if (copy_from_user(&session, arg, sizeof(session)))
- return -EFAULT;
- return opal_secure_erase_locking_range(dev, &session);
- }
+ switch (cmd) {
+ case IOC_OPAL_SAVE:
+ ret = opal_save(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_LOCK_UNLOCK:
+ ret = opal_lock_unlock(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_TAKE_OWNERSHIP:
+ ret = opal_take_ownership(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_ACTIVATE_LSP:
+ ret = opal_activate_lsp(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_SET_PW:
+ ret = opal_set_new_pw(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_ACTIVATE_USR:
+ ret = opal_activate_user(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_REVERT_TPR:
+ ret = opal_reverttper(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_LR_SETUP:
+ ret = opal_setup_locking_range(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_ADD_USR_TO_LR:
+ ret = opal_add_user_to_lr(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_ENABLE_DISABLE_MBR:
+ ret = opal_enable_disable_shadow_mbr(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_ERASE_LR:
+ ret = opal_erase_locking_range(dev, ioctl_ptr);
+ break;
+ case IOC_OPAL_SECURE_ERASE_LR:
+ ret = opal_secure_erase_locking_range(dev, ioctl_ptr);
+ break;
default:
pr_warn("No such Opal Ioctl %u\n", cmd);
}
- return -ENOTTY;
+
+ out:
+ kfree(ioctl_ptr);
+ return ret;
}
EXPORT_SYMBOL_GPL(sed_ioctl);
--
2.7.4