Bug 918

Summary:	Having read only file system will effectively disable sudo
Product:	Sudo	Reporter:	sudo
Component:	Sudoreplay	Assignee:	Todd C. Miller <Todd.Miller>
Status:	RESOLVED FIXED
Severity:	low
Priority:	low
Version:	1.8.21
Hardware:	PC
OS:	Linux

Description sudo 2020-03-01 04:06:06 MST

Hi.

I had a server turn the root file system into read only after a file system corruption and when I tried to investigate it using sudo, it no longer allows me to run any sudo commands as sudo quits saying that /var/log/sudo-io/ is read only and cannot be written with sudoreplay in effect.

Somehow I still could run 'sudo reboot' but is there a way to run sudo in these situations?

I do not really want non root users to be able to disable sudo logging as enforcing it was part of the reason I use it for security auditing.

I cannot think of a good way to circumvent but possibly write the log to memory (or a predefined tmpfs) until the file system becomes writeable again?

Thanks.

Comment 1 Todd C. Miller 2020-03-01 08:38:31 MST

If you set the ignore_iolog_errors flag in sudo, you will be able to run commands even when I/O logging cannot be performed.  E.g.

Defaults ignore_iolog_errors

The reason you could run reboot is  due to a line in sudoers that disables log_output for the reboot command.  Something like:

Cmnd_Alias    REBOOT = /sbin/halt, /sbin/reboot, /sbin/poweroff
Defaults!REBOOT !log_output

Comment 2 sudo 2020-03-01 08:59:12 MST

Thank you for the config tip!