sudo：/ usr / bin / sudo必须由uid 0拥有，并在chmod 755之后设置setuid位

Question

What i tried is this: https://stackoverflow.com/a/29903645/4983983

I executed this:

n=$(which node); \
n=${n%/bin/node}; \
chmod -R 755 $n/bin/*; \
sudo cp -r $n/{bin,lib,share} /usr/local

but now i can not execute for example sudo su command, i get following error:

 sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set 

I am not sure how can i redo it ?

EDIT: Regarding @Bodo answer:

sudo rpm --setperms mkdir
sudo rpm --setugids mkdir
cd /opt
 mkdir test13121
mkdir: cannot create directory ‘test13121’: Permission denied

BUT:

sudo  chown root:root /usr/bin/mkdir && sudo chmod 4755 /usr/bin/mkdir
mkdir test912121

Answer 1

The difficulty is to find out the normal permissions of the files you have changed.

You can try to reset the file permissions based on the information in the package management.

See eg https://www.cyberciti.biz/tips/reset-rhel-centos-fedora-package-file-permission.html

Citation from this page:

Reset the permissions of the all installed RPM packages

You need to use combination of rpm and a shell for loop command as follows:

 for p in $(rpm -qa); do rpm --setperms $p; done for p in $(rpm -qa); do rpm --setugids $p; done 

I suggest to read the linked page completely and try this for a single package first. I guess you can somehow ask rpm to find the package name that contains eg /usr/bin/sudo . and try if the commands work for a single package.

Edit: If the setuid or setgid bits are not correct, you can try to change the order of the commands and use --setugids before --setperms . (In some cases chown resets setuid or setgid bits; don't know if this applies to the rpm commands.)

There are sources in the internet that propose to combine --setugids and --setperms in one command or to use option -a instead of a loop like

rpm -a --setperms

Read the documentation. (I don't have an RPM based system where I could test the commands.)