This question already has an answer here:

Let's say user wants to execute a script test.sh but ls -l test.sh gives

 -rwxrwxr-- 1 root root 96 Feb 25 21:44 test.sh

Now if user doesn't want to make a copy of test.sh (on which he does chmod +x), he can simply do

sh test.sh

to execute test.sh.

Is there an analogue way to execute binary programs which one doesn't have execute permissions?

marked as duplicate by Jakuje, vonbrand, Scott, mdpc, Community Feb 27 '16 at 0:18

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 1
    sudo <program> - see man sudo – garethTheRed Feb 25 '16 at 21:09
  • @garethTheRed Doesn't work here for a script file; command not found. – Murphy Feb 26 '16 at 12:23
  • @Murphy - the OP asked for a way to do this with binary programs. – garethTheRed Feb 26 '16 at 13:20
  • @garethTheRed Tried it with a local copy of chmod, same result when the exec bits are unset. Perhaps this behaviour is controlled by a sudo setting? – Murphy Feb 26 '16 at 13:23
  • @Murphy - assume -rwxrwxr-- root root 86 Feb 25 21:44 test in /usr/bin. User doe doesn't have execute permission for this, but can run it with sudo test. Or have I misread the question? – garethTheRed Feb 26 '16 at 14:37

Basically this is the same thing as one of the very famous UNIX technical interview questions, known for ages:

Assume someone with root access ran a command chmod -R 444 / and made the chmod binary non-executable. How do you recover from it ?

There is a perl answer and there is this one, which basically is running a non-executable program, chmod in this case:

/lib/ld-linux.so /bin/chmod +x /bin/chmod

I think you can apply it to any other program that you know is executable. Otherwise be ready to embrace the disaster, which may ensue

PS> /lib/ld-linux.so might differ in name. So if the direct match is not available, look around for similarly named so's. For instance on my CentOS 6 server, it is /lib/ld-linux.so.2 which is a symlink pointing to /lib/ld-2.12.so. So, your mileage may vary.

  • 5
    Well, if you did a chmod -R 444 /, then /lib/ld-linux.so won't be executable either. If your (still running) shell is zsh, you can do zmodload zsh/files which gives you a builtin chmod. If it's ksh93, you can do command /opt/ast/bin/chmod to get a builtin chmod as well. – Stéphane Chazelas Feb 25 '16 at 21:28
  • 3
    Note that the ld-linux.so trick only works for dynamically linked programs. – Stéphane Chazelas Feb 25 '16 at 21:32
  • /lib/ld-linux.so.2 /bin/ls /bin/ls: error while loading shared libraries: /bin/ls: wrong ELF class: ELFCLASS64 – wolf-revo-cats Feb 26 '16 at 5:38
  • @viuser The command worked for me, and file returns the same ELF format on both files. – Murphy Feb 26 '16 at 14:12
  • @viuser try /lib/x86_64-linux-gnu/ld-2.19.so /bin/ls instead. The version in /lib is for 32-bit executables. – doneal24 Feb 26 '16 at 16:06

If the user doesn't have execute permission and cannot or is not willing to have it changed, then they must execute it as a group or user who does have execute permission.

If they know the root password then:

su -c <executable>

If they don't know the root password, but are trusted with sudo then:

sudo <executable>

If they don't know the root password and are not trusted with sudo privileges, then there is a reason why they should run the executable.

Not the answer you're looking for? Browse other questions tagged or ask your own question.