[PATCH 1/3 linux-next] udf: fix ioctl errors

[PATCH 1/3 linux-next] udf: fix ioctl errors

[Fabian Frederick]

Currently, lsattr for instance in udf directory gives
"udf: Invalid argument While reading flags on ..."

This patch returns -ENOIOCTLCMD
when command is unknown to have more accurate message like this:
"Inappropriate ioctl for device While reading flags on ..."

As suggested by Jan Kara, if arg is NULL with a correct ioctl,
we return -VM_FAULT_SIGBUS to report error.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
---
 fs/udf/file.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/udf/file.c b/fs/udf/file.c
index dbcb3a4a..d44b3cb 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -184,9 +184,10 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		goto out;
 	}
 
-	if (!arg) {
+	if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
+		     (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
 		udf_debug("invalid argument to udf_ioctl\n");
-		result = -EINVAL;
+		result = -VM_FAULT_SIGBUS;
 		goto out;
 	}
 
@@ -220,6 +221,8 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 				      UDF_I(inode)->i_ext.i_data,
 				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 		goto out;
+	default:
+		return -ENOIOCTLCMD;
 	}
 
 out:
-- 
2.9.3

[PATCH 2/3 linux-next] udf: simplify udf_ioctl()

[Fabian Frederick]

"out" label was only returning error code.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
---
 fs/udf/file.c | 39 +++++++++++++++------------------------
 1 file changed, 15 insertions(+), 24 deletions(-)

diff --git a/fs/udf/file.c b/fs/udf/file.c
index d44b3cb..00931fa 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -176,57 +176,48 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
 	long old_block, new_block;
-	int result = -EINVAL;
+	int result;
 
 	if (inode_permission(inode, MAY_READ) != 0) {
 		udf_debug("no permission to access inode %lu\n", inode->i_ino);
-		result = -EPERM;
-		goto out;
+		return -EPERM;
 	}
 
 	if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
 		     (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
 		udf_debug("invalid argument to udf_ioctl\n");
-		result = -VM_FAULT_SIGBUS;
-		goto out;
+		return -VM_FAULT_SIGBUS;
 	}
 
 	switch (cmd) {
 	case UDF_GETVOLIDENT:
 		if (copy_to_user((char __user *)arg,
 				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
-			result = -EFAULT;
+			return -EFAULT;
 		else
-			result = 0;
-		goto out;
+			return 0;
 	case UDF_RELOCATE_BLOCKS:
-		if (!capable(CAP_SYS_ADMIN)) {
-			result = -EPERM;
-			goto out;
-		}
-		if (get_user(old_block, (long __user *)arg)) {
-			result = -EFAULT;
-			goto out;
-		}
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (get_user(old_block, (long __user *)arg))
+			return -EFAULT;
+
 		result = udf_relocate_blocks(inode->i_sb,
 						old_block, &new_block);
 		if (result == 0)
 			result = put_user(new_block, (long __user *)arg);
-		goto out;
+
+		return result;
 	case UDF_GETEASIZE:
-		result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
-		goto out;
+		return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 	case UDF_GETEABLOCK:
-		result = copy_to_user((char __user *)arg,
+		return copy_to_user((char __user *)arg,
 				      UDF_I(inode)->i_ext.i_data,
 				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
-		goto out;
 	default:
 		return -ENOIOCTLCMD;
 	}
-
-out:
-	return result;
 }
 
 static int udf_release_file(struct inode *inode, struct file *filp)
-- 
2.9.3

[PATCH 3/3 linux-next] udf: remove else after return in udf_ioctl()

[Fabian Frederick]

else after return is not needed.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
---
 fs/udf/file.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/udf/file.c b/fs/udf/file.c
index 00931fa..a1fec1b 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -194,8 +194,7 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		if (copy_to_user((char __user *)arg,
 				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
 			return -EFAULT;
-		else
-			return 0;
+		return 0;
 	case UDF_RELOCATE_BLOCKS:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
-- 
2.9.3

Re: [PATCH 1/3 linux-next] udf: fix ioctl errors

[Jan Kara]

On Tue 24-01-17 21:48:34, Fabian Frederick wrote:
> Currently, lsattr for instance in udf directory gives
> "udf: Invalid argument While reading flags on ..."
> 
> This patch returns -ENOIOCTLCMD
> when command is unknown to have more accurate message like this:
> "Inappropriate ioctl for device While reading flags on ..."
> 
> As suggested by Jan Kara, if arg is NULL with a correct ioctl,
> we return -VM_FAULT_SIGBUS to report error.

You cannot return -VM_FAULT_SIGBUS from ioctl handler! Just look how it is
defined - it is an internal error code to the fault handling and in this
case would just get passed as is to userspace. Which suggests you didn't
test this check... Anyway, I've taken the patch and just removed the change
of the error code. Thanks.

								Honza

> 
> Signed-off-by: Fabian Frederick <fabf@skynet.be>
> ---
>  fs/udf/file.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/udf/file.c b/fs/udf/file.c
> index dbcb3a4a..d44b3cb 100644
> --- a/fs/udf/file.c
> +++ b/fs/udf/file.c
> @@ -184,9 +184,10 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  		goto out;
>  	}
>  
> -	if (!arg) {
> +	if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
> +		     (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
>  		udf_debug("invalid argument to udf_ioctl\n");
> -		result = -EINVAL;
> +		result = -VM_FAULT_SIGBUS;
>  		goto out;
>  	}
>  
> @@ -220,6 +221,8 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  				      UDF_I(inode)->i_ext.i_data,
>  				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
>  		goto out;
> +	default:
> +		return -ENOIOCTLCMD;
>  	}
>  
>  out:
> -- 
> 2.9.3
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 2/3 linux-next] udf: simplify udf_ioctl()

[Jan Kara]

On Tue 24-01-17 21:48:35, Fabian Frederick wrote:
> "out" label was only returning error code.
> 
> Signed-off-by: Fabian Frederick <fabf@skynet.be>

Thanks. I've taken this patch and squashed patch 3 into this one.

								Honza

> ---
>  fs/udf/file.c | 39 +++++++++++++++------------------------
>  1 file changed, 15 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/udf/file.c b/fs/udf/file.c
> index d44b3cb..00931fa 100644
> --- a/fs/udf/file.c
> +++ b/fs/udf/file.c
> @@ -176,57 +176,48 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  {
>  	struct inode *inode = file_inode(filp);
>  	long old_block, new_block;
> -	int result = -EINVAL;
> +	int result;
>  
>  	if (inode_permission(inode, MAY_READ) != 0) {
>  		udf_debug("no permission to access inode %lu\n", inode->i_ino);
> -		result = -EPERM;
> -		goto out;
> +		return -EPERM;
>  	}
>  
>  	if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
>  		     (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
>  		udf_debug("invalid argument to udf_ioctl\n");
> -		result = -VM_FAULT_SIGBUS;
> -		goto out;
> +		return -VM_FAULT_SIGBUS;
>  	}
>  
>  	switch (cmd) {
>  	case UDF_GETVOLIDENT:
>  		if (copy_to_user((char __user *)arg,
>  				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
> -			result = -EFAULT;
> +			return -EFAULT;
>  		else
> -			result = 0;
> -		goto out;
> +			return 0;
>  	case UDF_RELOCATE_BLOCKS:
> -		if (!capable(CAP_SYS_ADMIN)) {
> -			result = -EPERM;
> -			goto out;
> -		}
> -		if (get_user(old_block, (long __user *)arg)) {
> -			result = -EFAULT;
> -			goto out;
> -		}
> +		if (!capable(CAP_SYS_ADMIN))
> +			return -EPERM;
> +
> +		if (get_user(old_block, (long __user *)arg))
> +			return -EFAULT;
> +
>  		result = udf_relocate_blocks(inode->i_sb,
>  						old_block, &new_block);
>  		if (result == 0)
>  			result = put_user(new_block, (long __user *)arg);
> -		goto out;
> +
> +		return result;
>  	case UDF_GETEASIZE:
> -		result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
> -		goto out;
> +		return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
>  	case UDF_GETEABLOCK:
> -		result = copy_to_user((char __user *)arg,
> +		return copy_to_user((char __user *)arg,
>  				      UDF_I(inode)->i_ext.i_data,
>  				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
> -		goto out;
>  	default:
>  		return -ENOIOCTLCMD;
>  	}
> -
> -out:
> -	return result;
>  }
>  
>  static int udf_release_file(struct inode *inode, struct file *filp)
> -- 
> 2.9.3
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR