Re: [PATCH v4] rt: fix shm_open not set ENAMETOOLONG when name exceeds {_POSIX_PATH_MAX}

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 07/03/23 09:16, abushwang wrote:
> according to man-pages-posix-2017, shm_open() function may fail if the length
> of the name argument exceeds {_POSIX_PATH_MAX} and set ENAMETOOLONG
> 
> Signed-off-by: abushwang <abushwangs@gmail.com>

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  posix/shm-directory.c      | 12 +++++++++---
>  rt/shm_open.c              |  5 +++--
>  sysdeps/pthread/sem_open.c |  5 +++--
>  3 files changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/posix/shm-directory.c b/posix/shm-directory.c
> index 86d9fd8e4f..f130bab3c2 100644
> --- a/posix/shm-directory.c
> +++ b/posix/shm-directory.c
> @@ -25,6 +25,7 @@
>  #include <string.h>
>  #include <sys/mman.h>
>  #include <fcntl.h>
> +#include <errno.h>
>  
>  int
>  __shm_get_name (struct shmdir_name *result, const char *name, bool sem_prefix)
> @@ -54,9 +55,14 @@ __shm_get_name (struct shmdir_name *result, const char *name, bool sem_prefix)
>    if (sem_prefix)
>      alloc_buffer_copy_bytes (&buffer, "sem.", strlen ("sem."));
>    alloc_buffer_copy_bytes (&buffer, name, namelen + 1);
> -  if (namelen == 0 || memchr (name, '/', namelen) != NULL
> -      || alloc_buffer_has_failed (&buffer))
> -    return -1;
> +  if (namelen == 0 || memchr (name, '/', namelen) != NULL)
> +    return EINVAL;
> +  if (alloc_buffer_has_failed (&buffer))
> +    {
> +      if (namelen > NAME_MAX)
> +        return ENAMETOOLONG;
> +      return EINVAL;
> +    }
>    return 0;
>  }
>  libc_hidden_def (__shm_get_name)

Ok.

> diff --git a/rt/shm_open.c b/rt/shm_open.c
> index 6c1f4d604f..fc1dc96bb4 100644
> --- a/rt/shm_open.c
> +++ b/rt/shm_open.c
> @@ -30,9 +30,10 @@ int
>  __shm_open (const char *name, int oflag, mode_t mode)
>  {
>    struct shmdir_name dirname;
> -  if (__shm_get_name (&dirname, name, false) != 0)
> +  int ret =__shm_get_name (&dirname, name, false);
> +  if (ret != 0)
>      {
> -      __set_errno (EINVAL);
> +      __set_errno (ret);
>        return -1;
>      }
>  
> diff --git a/sysdeps/pthread/sem_open.c b/sysdeps/pthread/sem_open.c
> index 2551b035e1..2d32a13557 100644
> --- a/sysdeps/pthread/sem_open.c
> +++ b/sysdeps/pthread/sem_open.c
> @@ -47,9 +47,10 @@ __sem_open (const char *name, int oflag, ...)
>      }
>  
>    struct shmdir_name dirname;
> -  if (__shm_get_name (&dirname, name, true) != 0)
> +  int ret = __shm_get_name (&dirname, name, true);
> +  if (ret != 0)
>      {
> -      __set_errno (EINVAL);
> +      __set_errno (ret);
>        return SEM_FAILED;
>      }
>  

Ok.