Re: [PATCH] udf: use strscpy() instead of strcpy() for regid ident field

[David Laight]

On Sat, 27 Jun 2026 18:19:48 +0000
Mahad Ibrahim <mahad.ibrahim.dev@xxxxxxxxx> wrote:

> strcpy() is deprecated as it performs no bounds checking. Replace the
> three call sites that copy UDF_ID_DEVELOPER into the regid ident field
> with strscpy().

There is no real reason to disallow use of strcpy() to copy constant
strings into arrays.
The compiler (or rather the header files) can allow such safe uses
while rejecting ones that might potentially overflow.

Additionally if the fixed string is too long the compiler will generate
an error for strcpy() whereas strscpy() will truncate the copy.

So this change really is pointless churn.

	David

> 
> The current string fits the field with room to spare, so there is no
> overflow today. strscpy() bounds the copy to the destination and
> NUL-terminates, keeping it safe if the string or the field size
> changes later.
> 
> Signed-off-by: Mahad Ibrahim <mahad.ibrahim.dev@xxxxxxxxx>
> ---
>  fs/udf/inode.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/udf/inode.c b/fs/udf/inode.c
> index 67bcf83758c8..3140e001b315 100644
> --- a/fs/udf/inode.c
> +++ b/fs/udf/inode.c
> @@ -1809,7 +1809,7 @@ static int udf_update_inode(struct inode *inode, int do_sync)
>  		}
>  		eid = (struct regid *)dsea->impUse;
>  		memset(eid, 0, sizeof(*eid));
> -		strcpy(eid->ident, UDF_ID_DEVELOPER);
> +		strscpy(eid->ident, UDF_ID_DEVELOPER, sizeof(eid->ident));
>  		eid->identSuffix[0] = UDF_OS_CLASS_UNIX;
>  		eid->identSuffix[1] = UDF_OS_ID_LINUX;
>  		dsea->majorDeviceIdent = cpu_to_le32(imajor(inode));
> @@ -1833,7 +1833,7 @@ static int udf_update_inode(struct inode *inode, int do_sync)
>  		udf_time_to_disk_stamp(&fe->modificationTime, inode_get_mtime(inode));
>  		udf_time_to_disk_stamp(&fe->attrTime, inode_get_ctime(inode));
>  		memset(&(fe->impIdent), 0, sizeof(struct regid));
> -		strcpy(fe->impIdent.ident, UDF_ID_DEVELOPER);
> +		strscpy(fe->impIdent.ident, UDF_ID_DEVELOPER, sizeof(fe->impIdent.ident));
>  		fe->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
>  		fe->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
>  		fe->uniqueID = cpu_to_le64(iinfo->i_unique);
> @@ -1872,7 +1872,7 @@ static int udf_update_inode(struct inode *inode, int do_sync)
>  		udf_time_to_disk_stamp(&efe->attrTime, inode_get_ctime(inode));
>  
>  		memset(&(efe->impIdent), 0, sizeof(efe->impIdent));
> -		strcpy(efe->impIdent.ident, UDF_ID_DEVELOPER);
> +		strscpy(efe->impIdent.ident, UDF_ID_DEVELOPER, sizeof(efe->impIdent.ident));
>  		efe->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
>  		efe->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
>  		efe->uniqueID = cpu_to_le64(iinfo->i_unique);