Re: [Bugme-new] [Bug 10284] New: executables with read bit 'off' cannot open /dev/stdin

[Matthew Wilcox <matthew@wil.cx>]

On Wed, Mar 19, 2008 at 02:31:08PM -0700, Andrew Morton wrote:
> (switched to email.  Please respond via emailed reply-to-all, not via the
> bugzilla web interface).

Unfortunately, Joe seems not to be able to follow that instruction.
He's left two comments in bugzilla which are not reflected in this email
thread.

> >      KernelVersion: 2.6.16.27-0.9-smp
> > A short program that calls open on /dev/stdin:
> > 
> > cat open_stdin.c
> > #include <stdio.h>
> > #include <stdlib.h>
> > #include <sys/types.h>
> > #include <sys/stat.h>
> > #include <fcntl.h>
> > 
> > int main(int argc, char **argv) {
> >   open("/dev/stdin",O_RDONLY);
> >   return 0;
> > }

I've tried this program on 2.6.25-rc3-00093-g59e1338-dirty and it does
not fail.

> > open("/dev/stdin", O_RDONLY)            = -1 EACCES (Permission denied)

Specifically, my tests show:

open-stdin-readable:open("/dev/stdin", O_RDONLY)            = 3
open-stdin-unreadable:open("/dev/stdin", O_RDONLY)            = 3

Joe, can you try a more recent kernel?

Another thing to try would be opening /proc/self/fd/0 or /dev/pts/0
in your program and seeing whether those fail.

-- 
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