Install -S Not Safe was: Re: Installworld deletes libc

[Jeremy Chadwick]

On Sun, Sep 21, 2008 at 04:06:33PM -0700, Jason C. Wells wrote:
> Jason C. Wells wrote:
>> Jason C. Wells wrote:
>
>> I should add that 'systcl security.jail.chflags_allowed=1' allowed  
>> installworld to proceed without error. That solves my immediate 
>> problem.  There appears to be a bug in the security mechanism.
>
> The reason there appeared to be a bug in the security mechanism is that  
> I performed (IIRC) chflags -noschg on libc as root on the host system  
> outside the jail.
>
> But for some reason 'install -S' was not safe.
>
> (outside the jail)
> ~$ chflags noschg /usr/jails/cr/lib/libc.so.6
>
> (inside the jail)
> [root at s4cr /usr/src/lib/libc]# ls -lao /lib/libc.so.6
> -rwxr-xr-x  1 root  wheel  - 981331 Sep 21 15:57 /lib/libc.so.6
>
> [root at s4cr /usr/src/lib/libc]# sysctl -a | grep secur
> kern.securelevel: -1
> security.jail.chflags_allowed: 0
>
> [root at s4cr /usr/src/lib/libc]#   make install
> install -C -o root -g wheel -m 444   libc.a /usr/lib
> install -C -o root -g wheel -m 444   libc_p.a /usr/lib
> install -s -o root -g wheel -m 444   -fschg -S  libc.so.6 /lib
> install: /lib/libc.so.6: chflags: Operation not permitted
> *** Error code 71
>
> Stop in /usr/src/lib/libc.
>
> [root at s4cr /usr/src/lib/libc]# ls -lao /lib/libc.so.6
> /libexec/ld-elf.so.1: Shared object "libc.so.6" not found, required by "ls"
> [root at s4cr /usr/src/lib/libc]#

Please file a PR on this matter.

-- 
| Jeremy Chadwick                                jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |