Messages in this thread | | | Date | Thu, 25 Sep 2014 16:31:22 +0200 | Subject | Re: [PATCH] vfs: fix linkat error for unprivileged AT_EMPTY_PATH | From | Miklos Szeredi <> |
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On Wed, Sep 24, 2014 at 9:00 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > On Wed, Sep 24, 2014 at 05:25:23PM +0200, Miklos Szeredi wrote: >> From: Miklos Szeredi <mszeredi@suse.cz> >> >> Return proper error value for linkat(..., AT_EMPTY_PATH) without enough >> privileges. >> >> I guess ENOENT was used here, because without AT_EMPTY_PATH that's what >> we'd return for an empty path. But it is wrong for AT_EMPTY_PATH, since we >> might not even be passing an empty path, we are simply complaining about >> lack of privs for which EPERM is the proper error. > > Umm... Are you sure that nothing in userland is checking for that > return value? I agree that EPERM would make more sense, but...
How could I be sure?
But does it even make sense to check for that error value? I don't think it is, since we have never allowed unprivileged AT_EMPTY_PATH for linkat (except by bb2314b4799649 which was reverted before being included in a release).
So if when (if ever) we do allow that, *then* testing for an error value will make sense. But surely if one is writing code which can't even be tested, then it won't come as a big surprise if it will eventually fail...
Thanks, Miklos
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