sudo problem on restore from archive

[Robert McBroom]

On a system restore from a tar archive sudo won't work. Says 
/usr/bin/sudo  needs to be owned by 0 with the suid bit set. Root owns 
the file and is 0. Looking at a working system directory list shows

   -rwsr-xr-x.  1 root root       57456 Aug 16 20:00 su
   ---s--x--x.  1 root root      202872 Jul 24 20:00 sudo

How does that s bit get set?

[Mike Wright]

On 12/30/23 15:13, Robert McBroom via users wrote:
>  On a system restore from a tar archive sudo won't work. Says 
>  /usr/bin/sudo  needs to be owned by 0 with the suid bit set. Root owns 
>  the file and is 0. Looking at a working system directory list shows
>  
>     -rwsr-xr-x.  1 root root       57456 Aug 16 20:00 su
>     ---s--x--x.  1 root root      202872 Jul 24 20:00 sudo
>  
>  How does that s bit get set? 
man chmod, paragraph 2

[Robert McBroom]

On 12/30/23 18:18, Mike Wright wrote:
>  On 12/30/23 15:13, Robert McBroom via users wrote:
> > On a system restore from a tar archive sudo won't work. Says 
> > /usr/bin/sudo  needs to be owned by 0 with the suid bit set. Root 
> > owns the file and is 0. Looking at a working system directory list shows
> >
> >    -rwsr-xr-x.  1 root root       57456 Aug 16 20:00 su
> >    ---s--x--x.  1 root root      202872 Jul 24 20:00 sudo
> >
> > How does that s bit get set?
>
>  man chmod, paragraph 2
>  
The error message is about an suid bit while the man page talks about 
setuid, trying it works. Not a clear extension over the old 777.

[Mike Wright]

On 12/30/23 20:48, Robert McBroom via users wrote:
>  
>  On 12/30/23 18:18, Mike Wright wrote:
> > On 12/30/23 15:13, Robert McBroom via users wrote:
> >> On a system restore from a tar archive sudo won't work. Says 
> >> /usr/bin/sudo  needs to be owned by 0 with the suid bit set. Root 
> >> owns the file and is 0. Looking at a working system directory list shows
> >>
> >>    -rwsr-xr-x.  1 root root       57456 Aug 16 20:00 su
> >>    ---s--x--x.  1 root root      202872 Jul 24 20:00 sudo
> >>
> >> How does that s bit get set?
> >
> > man chmod, paragraph 2
> >
>  The error message is about an suid bit while the man page talks about 
>  setuid, trying it works. Not a clear extension over the old 777. 
chown 0:0 /usr/bin/sudo root root
chmod 755 /usr/bin/sudo rwxr-xr-x
chmod u+s /usr/bin/sudo rwsr-xr-x

[Jon LaBadie]

On Sat, Dec 30, 2023 at 11:48:31PM -0500, Robert McBroom via users wrote:
> On 12/30/23 18:18, Mike Wright wrote:
> > On 12/30/23 15:13, Robert McBroom via users wrote:
> >> On a system restore from a tar archive sudo won't work. Says
> >> /usr/bin/sudo  needs to be owned by 0 with the suid bit set. Root
> >> owns the file and is 0. Looking at a working system directory list shows
> >>
> >>    -rwsr-xr-x.  1 root root       57456 Aug 16 20:00 su
> >>    ---s--x--x.  1 root root      202872 Jul 24 20:00 sudo
> >>
> >> How does that s bit get set?
> >
> > man chmod, paragraph 2
> >
> The error message is about an suid bit while the man page talks about
> setuid, trying it works. Not a clear extension over the old 777. 
# chmod 4755 /bin/su
# chmod 4111 /bin/sudo

The suid (setuid), sgid (setgid), and sticky bit are an additional
3 binary bits above the owners permissions.  4=suid, 2=sgid, 1=sticky

-- 
Jon H. LaBadie                  jonfu(a)jgcomp.com

[Samuel Sieb]

On 12/30/23 15:13, Robert McBroom via users wrote:
>  On a system restore from a tar archive sudo won't work. Says 
>  /usr/bin/sudo  needs to be owned by 0 with the suid bit set. Root owns 
>  the file and is 0. Looking at a working system directory list shows
>  
>     -rwsr-xr-x.  1 root root       57456 Aug 16 20:00 su
>     ---s--x--x.  1 root root      202872 Jul 24 20:00 sudo
>  
>  How does that s bit get set? 
chmod u+s filename
Of course you have to run that as root.  I hope you have some way to get 
to root other than sudo.

[Sam Varshavchik]

Robert McBroom via users writes:

>  On a system restore from a tar archive sudo won't work. Says
> /usr/bin/sudo   
>  needs to be owned by 0 with the suid bit set. Root owns the file and is 0.  
>  Looking at a working system directory list shows
>
>    -rwsr-xr-x.  1 root root       57456 Aug 16 20:00 su
>    ---s--x--x.  1 root root      202872 Jul 24 20:00 sudo
>
>  How does that s bit get set? 
By chmod u+s

But there might be a better way to salvage your system, try:

rpm --restore -a