Re: [PATCH v2] linux: Make fdopendir fail with O_PATH (BZ 30373)

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

On 30/11/23 06:54, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>> diff --git a/sysdeps/unix/sysv/linux/fdopendir.c b/sysdeps/unix/sysv/linux/fdopendir.c
>> index 861345396c..707fb5960e 100644
>> --- a/sysdeps/unix/sysv/linux/fdopendir.c
>> +++ b/sysdeps/unix/sysv/linux/fdopendir.c
>> @@ -37,10 +37,16 @@ __fdopendir (int fd)
>>        return NULL;
>>      }
>>  
>> -  /* Make sure the descriptor allows for reading.  */
>>    int flags = __fcntl64_nocancel (fd, F_GETFL);
>>    if (__glibc_unlikely (flags == -1))
>>      return NULL;
>> +  /* Fail early for descriptors opened with O_PATH.  */
>> +  if (__glibc_unlikely (flags & O_PATH))
>> +    {
>> +      __set_errno (EBADF);
>> +      return NULL;
>> +    }
> 
> Should we fail with EINVAL instead of EBADF?

POSIX states it should be EBADF indeed, as Paul has noted [1].  The EINVAL
returns is a different issue.

> 
> Maybe add a comment that EBADF matches what readdir will fail with?
> 
> Otherwise:
> 
> Reviewed-by: Florian Weimer <fweimer@redhat.com>

Thanks.

> 
> Thanks,
> Florian
> 

[1] https://sourceware.org/pipermail/libc-alpha/2023-September/151302.html