From: Al Viro <viro@ZenIV.linux.org.uk>
To: Andy Lutomirski <luto@kernel.org>
Cc: Linux API <linux-api@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>
Subject: Re: new ...at() flag: AT_NO_JUMPS
Date: Sun, 30 Apr 2017 00:25:04 +0100 [thread overview]
Message-ID: <20170429232504.GU29622@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CALCETrXhOhG0tRDDOROwT9ghvQvKziM2PBN=CX5Soa2m7=0cFw@mail.gmail.com>
On Sat, Apr 29, 2017 at 04:17:18PM -0700, Andy Lutomirski wrote:
> On Sat, Apr 29, 2017 at 3:04 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> > New AT_... flag - AT_NO_JUMPS
> >
> > Semantics: pathname resolution must not involve
> > * traversals of absolute symlinks
> > * traversals of procfs-style symlinks
> > * traversals of mountpoints (including bindings, referrals, etc.)
> > * traversal of .. in the starting point of pathname resolution.
>
> Can you clarify this last one? I assume that ".." will be rejected,
> but what about "a/../.."? How about "b" if b is a symlink to ".."?
> How about "a/b" if a is a directory and b is a symlink to "../.."?
All of those will be rejected - in each of those cases pathname traversal
leads back into the starting point with .. being the next component to
handle.
WARNING: multiple messages have this Message-ID (diff)
From: Al Viro <viro-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
To: Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Linux FS Devel
<linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: new ...at() flag: AT_NO_JUMPS
Date: Sun, 30 Apr 2017 00:25:04 +0100 [thread overview]
Message-ID: <20170429232504.GU29622@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CALCETrXhOhG0tRDDOROwT9ghvQvKziM2PBN=CX5Soa2m7=0cFw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Sat, Apr 29, 2017 at 04:17:18PM -0700, Andy Lutomirski wrote:
> On Sat, Apr 29, 2017 at 3:04 PM, Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org> wrote:
> > New AT_... flag - AT_NO_JUMPS
> >
> > Semantics: pathname resolution must not involve
> > * traversals of absolute symlinks
> > * traversals of procfs-style symlinks
> > * traversals of mountpoints (including bindings, referrals, etc.)
> > * traversal of .. in the starting point of pathname resolution.
>
> Can you clarify this last one? I assume that ".." will be rejected,
> but what about "a/../.."? How about "b" if b is a symlink to ".."?
> How about "a/b" if a is a directory and b is a symlink to "../.."?
All of those will be rejected - in each of those cases pathname traversal
leads back into the starting point with .. being the next component to
handle.
next prev parent reply other threads:[~2017-04-29 23:25 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-29 22:04 new ...at() flag: AT_NO_JUMPS Al Viro
2017-04-29 22:04 ` Al Viro
2017-04-29 23:17 ` Andy Lutomirski
2017-04-29 23:17 ` Andy Lutomirski
2017-04-29 23:25 ` Al Viro [this message]
2017-04-29 23:25 ` Al Viro
2017-04-30 1:13 ` Andy Lutomirski
2017-04-30 4:38 ` Matthew Wilcox
2017-04-30 4:38 ` Matthew Wilcox
2017-04-30 16:10 ` Al Viro
2017-04-30 16:10 ` Al Viro
2017-05-01 4:52 ` Andy Lutomirski
2017-05-01 5:15 ` Al Viro
2017-05-01 5:15 ` Al Viro
2017-05-01 17:36 ` Jann Horn
2017-05-01 19:37 ` Andy Lutomirski
2017-05-05 0:30 ` Al Viro
2017-05-05 0:30 ` Al Viro
2017-05-05 0:44 ` Andy Lutomirski
2017-05-05 1:06 ` Al Viro
2017-05-05 1:27 ` Linus Torvalds
2017-05-05 1:27 ` Linus Torvalds
2017-05-05 3:00 ` Al Viro
2017-05-05 3:00 ` Al Viro
2017-05-05 4:01 ` Linus Torvalds
2017-05-05 4:31 ` Andy Lutomirski
2017-05-05 2:47 ` Jann Horn
2017-05-05 3:46 ` Linus Torvalds
2017-05-05 4:39 ` Al Viro
2017-05-05 4:39 ` Al Viro
2017-05-05 4:44 ` Andy Lutomirski
2017-05-05 20:04 ` Eric W. Biederman
2017-05-05 20:04 ` Eric W. Biederman
2017-05-05 20:28 ` Eric W. Biederman
2017-05-08 19:34 ` Mickaël Salaün
2017-05-08 19:34 ` Mickaël Salaün
2017-05-18 8:50 ` David Drysdale
2017-09-10 20:26 Jürg Billeter
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