svn commit: r318313 - head/libexec/rtld-elf

[Konstantin Belousov]

On Mon, May 15, 2017 at 07:42:23PM +0000, Alexey Dokuchaev wrote:
> On Mon, May 15, 2017 at 10:40:49PM +0300, Konstantin Belousov wrote:
> > On Mon, May 15, 2017 at 03:37:42PM -0400, Nikolai Lifanov wrote:
> > > On 05/15/2017 15:36, Alexey Dokuchaev wrote:
> > > > ...
> > > > Would this now allow executing binaries (with or without +x bit) from
> > > > filesystems mounted with -o noexec?
> > > 
> > > No:
> > > 
> > > # zfs create -o mountpoint=/mnt -o exec=off tank/TEST
> > > # cp /bin/sh /mnt/
> > > # /mnt/sh
> > > /mnt/sh: Permission denied.
> > > # /libexec/ld-elf.so.1 /mnt/sh
> > > /mnt/sh: mmap of data failed: Permission denied
> > 
> > This is due to
> > r313967 | kib | 2017-02-19 22:51:04 +0200 (Sun, 19 Feb 2017) | 24 lines
> > Apply noexec mount option for mmap(PROT_EXEC).
> 
> Nice, good to know that.

[Replying to random mail in thread]

I tried this on an up to date latest Fedora installation:
[kostik at sandy ~]$ cp /bin/ls /tmp
[kostik at sandy ~]$ chmod a-x /tmp/ls
[kostik at sandy ~]$ /lib64/ld-linux-x86-64.so.2  /tmp/ls
Dropbox  intel  tmp  work

I am not sure about one detail, the /tmp/ls file has some security context
on it, but I do not believe that it may affect the outcome of the experiment.
Please correct me if I am wrong.