Re: [PATCH] vfs: new O_NODE open flag

Andreas Gruenbacher
2009-10-14T13:17:34Z

On Monday 28 September 2009 18:04:10 Miklos Szeredi wrote:
> The point of the above example was that reopening a file descriptor
> with upgraded (or downgraded) access mode is even now possible. Which
> either means:
>
> a) the current permission model under /proc/PID/fd has a security
> hole (which Jamie is worried about)

No worries -- access to /proc/PID/fd/* requires ptrace access to PID, so we do
not have a security hole here. The ptrace checks were introduced here:

778c1144771f0064b6f51bee865cceb0d996f2f9
df26c40e567356caeefe2861311e19c54444d917

Cheers,
Andreas