Ubuntu notes sudo Permissions

Accidentally set all the files and directories under/usr to my own user as the owner. In this case, the sudo: mustsetuidroot prompt will be displayed during sudo. The solution is to set the/usr/bin/sudo permission, and sudo is required during the setting, which is a problem of chicken and eggs. At this time, you can enter the recovery mode, change its owner to root, and change the execution permission to s-x, which solves the problem. Similarly, because I have modified the execution permissions of files under/usr (the Network accidentally sets all files and directories under/usr to my own user as the owner, in this case, sudo: must setuid root will be prompted during sudo.

The solution is to set the/usr/bin/sudo permission, and sudo is required during the setting, which is a problem of chicken and eggs.

At this time, you can enter the recovery mode, change its owner to root, and change the execution permission to s-x, which solves the problem.

Similarly, because I modified the File Execution permissions under/usr (some friends on the Internet also had misoperations or some inexplicable problems), usb cannot be automatically mounted, the reason is that you need to use/usr/bin/pmount for usb mounting. You only need to modify its permissions:

Chmod 4755 pmount.

I saw a lot of people asking for help, but there was little solution. One of shuimu's buddies advised me to reinstall the system. First, my machine does not have an optical drive. If I reinstall it, it will be troublesome. Secondly, if Ubuntu is really so weak, it will not be today.

Now, I am a user of ubuntu release!