Re: [PATCH] fs: Fix filename init after recent refactoring

[Mateusz Guzik]

ouch, I'm so sorry :)

On Thu, Apr 10, 2025 at 12:05 AM Song Liu <song@xxxxxxxxxx> wrote:
>
> getname_flags() should save __user pointer "filename" in filename->uptr.
> However, this logic is broken by a recent refactoring. Fix it by passing
> __user pointer filename to helper initname().
>
> Fixes: 611851010c74 ("fs: dedup handling of struct filename init and refcounts bumps")
> Cc: Mateusz Guzik <mjguzik@xxxxxxxxx>
> Cc: Christian Brauner <brauner@xxxxxxxxxx>
> Signed-off-by: Song Liu <song@xxxxxxxxxx>
> ---
>  fs/namei.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/namei.c b/fs/namei.c
> index 360a86ca1f02..8510ff53f12e 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -125,9 +125,9 @@
>
>  #define EMBEDDED_NAME_MAX      (PATH_MAX - offsetof(struct filename, iname))
>
> -static inline void initname(struct filename *name)
> +static inline void initname(struct filename *name, const char __user *uptr)
>  {
> -       name->uptr = NULL;
> +       name->uptr = uptr;
>         name->aname = NULL;
>         atomic_set(&name->refcnt, 1);
>  }
> @@ -210,7 +210,7 @@ getname_flags(const char __user *filename, int flags)
>                         return ERR_PTR(-ENAMETOOLONG);
>                 }
>         }
> -       initname(result);
> +       initname(result, filename);
>         audit_getname(result);
>         return result;
>  }
> @@ -268,7 +268,7 @@ struct filename *getname_kernel(const char * filename)
>                 return ERR_PTR(-ENAMETOOLONG);
>         }
>         memcpy((char *)result->name, filename, len);
> -       initname(result);
> +       initname(result, NULL);
>         audit_getname(result);
>         return result;
>  }
> --
> 2.47.1
>


-- 
Mateusz Guzik <mjguzik gmail.com>