Re: [PATCH] lightnvm: centralize permission check for lightnvm ioctl

[Matias Bjørling]

On 02/26/2018 01:11 PM, Johannes Thumshirn wrote:

Currently all functions for handling the lightnvm core ioctl commands
do a check for CAP_SYS_ADMIN.

Change this to fail early in nvm_ctl_ioctl(), so we don't have to
duplicate the permission checks all over.

Signed-off-by: Johannes Thumshirn <jthumsh...@suse.de>
---
  drivers/lightnvm/core.c | 21 +++------------------
  1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index dcc9e621e651..74d0bda94c11 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -1040,9 +1040,6 @@ static long nvm_ioctl_info(struct file *file, void __user 
*arg)
        struct nvm_tgt_type *tt;
        int tgt_iter = 0;

- if (!capable(CAP_SYS_ADMIN))

-               return -EPERM;
-
        info = memdup_user(arg, sizeof(struct nvm_ioctl_info));
        if (IS_ERR(info))
                return -EFAULT;
@@ -1081,9 +1078,6 @@ static long nvm_ioctl_get_devices(struct file *file, void 
__user *arg)
        struct nvm_dev *dev;
        int i = 0;

- if (!capable(CAP_SYS_ADMIN))

-               return -EPERM;
-
        devices = kzalloc(sizeof(struct nvm_ioctl_get_devices), GFP_KERNEL);
        if (!devices)
                return -ENOMEM;
@@ -1124,9 +1118,6 @@ static long nvm_ioctl_dev_create(struct file *file, void 
__user *arg)
  {
        struct nvm_ioctl_create create;

- if (!capable(CAP_SYS_ADMIN))

-               return -EPERM;
-
        if (copy_from_user(&create, arg, sizeof(struct nvm_ioctl_create)))
                return -EFAULT;

@@ -1162,9 +1153,6 @@ static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)

        struct nvm_dev *dev;
        int ret = 0;

- if (!capable(CAP_SYS_ADMIN))

-               return -EPERM;
-
        if (copy_from_user(&remove, arg, sizeof(struct nvm_ioctl_remove)))
                return -EFAULT;

@@ -1189,9 +1177,6 @@ static long nvm_ioctl_dev_init(struct file *file, void __user *arg)

  {
        struct nvm_ioctl_dev_init init;

- if (!capable(CAP_SYS_ADMIN))

-               return -EPERM;
-
        if (copy_from_user(&init, arg, sizeof(struct nvm_ioctl_dev_init)))
                return -EFAULT;

@@ -1208,9 +1193,6 @@ static long nvm_ioctl_dev_factory(struct file *file, void __user *arg)

  {
        struct nvm_ioctl_dev_factory fact;

- if (!capable(CAP_SYS_ADMIN))

-               return -EPERM;
-
        if (copy_from_user(&fact, arg, sizeof(struct nvm_ioctl_dev_factory)))
                return -EFAULT;

@@ -1226,6 +1208,9 @@ static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)

  {
        void __user *argp = (void __user *)arg;

+ if (!capable(CAP_SYS_ADMIN))

+               return -EPERM;
+
        switch (cmd) {
        case NVM_INFO:
                return nvm_ioctl_info(file, argp);

Thanks Johannes. Applied.