Comment # 10 on bug 1186781 from Usr Merge

(In reply to Usr Merge from comment #9)
> I found that the only reference to ld-linux-x86-64 in /etc/ld.so.cache is
> /usr/lib64/ld-linux-x86-64.so.2, so do the broken links in /lib64 even
> matter?

They do seem to matter. I can use /usr/lib64/ld-linux-x86-64.so.2 to run
executables directly:

$ /usr/lib64/ld-linux-x86-64.so.2 /usr/bin/ls

Here is how I get a list of libraries used by ls:

$ /usr/lib64/ld-linux-x86-64.so.2 /usr/bin/bash ~/bin/ldd /bin/ls
        linux-vdso.so.1 (0x00007ffd3c56d000)
        libselinux.so.1 => /usr/lib64/libselinux.so.1 (0x00007f54e22db000)
        libcap.so.2 => /usr/lib64/libcap.so.2 (0x00007f54e22d0000)
        libc.so.6 => /usr/lib64/libc.so.6 (0x00007f54e2101000)
        libpcre2-8.so.0 => /usr/lib64/libpcre2-8.so.0 (0x00007f54e204b000)
        libdl.so.2 => /usr/lib64/libdl.so.2 (0x00007f54e2044000)
        /lib64/ld-linux-x86-64.so.2 => /usr/lib64/ld-linux-x86-64.so.2
(0x00007f54e2360000)

where ~/bin/ldd is the shell script /usr/bin/ldd with
/usr/lib64/ld-linux-x86-64.so.2 appended to the variable RTLDLIST. Note the
difference to the example in the man page of ldd, which has
/lib64/ld-linux-x86-64.so.2 without a "=>".

This trick allows me to start user programs, but unfortunately, I can still get
no root access for reasons I don't understand:

$ /usr/lib64/ld-linux-x86-64.so.2 /usr/bin/su
Password: 
su: Authentication service cannot retrieve authentication info
$ /usr/lib64/ld-linux-x86-64.so.2 /usr/bin/sudo
sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the
'nosuid' option set or an NFS file system without root privileges?