[SOLVED] Problem about noexec option in /etc/fstab

jcky · 09-11-2009, 03:29 AM

Hi all,
I set the noexec option in the /etc/fstab and then mount the nfs directory. I copied an rpm package from dvd to nfs server shared folder. Then I executed the rpm package from cilent. But it did work!
Who can explain that strange phenomenon?
Thanks in advance!

kilgoretrout · 09-11-2009, 06:16 AM

The executable was on the client, not the NTFS server. The rpm command is on the client box, not the server so you are not running an executable on the server.

jcky · 09-11-2009, 09:07 AM

Hi ,
I made you misunderstood. I used executable command on the client but not server.

r3sistance · 09-11-2009, 10:51 AM

Quote:

Originally Posted by jcky

Hi ,
I made you understood. I used executable command on the client but not server.

you failed to understand the point, the package itself isn't an executable, RPM was used on the client and is stored on the client, all you did was point RPM to USE the package the package itself did nothing and did NOT execute as the RPM executable on the client did all the work. If the RPM executable was on the server and you tried executing that, then that is what would not work, but that's not what you are doing. Your using RPM on a client machine where executables are allowed.

jcky · 09-11-2009, 07:01 PM

Quote:

Originally Posted by r3sistance

you failed to understand the point, the package itself isn't an executable, RPM was used on the client and is stored on the client, all you did was point RPM to USE the package the package itself did nothing and did NOT execute as the RPM executable on the client did all the work. If the RPM executable was on the server and you tried executing that, then that is what would not work, but that's not what you are doing. Your using RPM on a client machine where executables are allowed.

Hi,
But the rpm package was in the nfs shared directory!(meant on the server). And I mounted the shared directory and then execute the rpm package...

michaelk · 09-11-2009, 07:15 PM

Let me try...
A file called filename.rpm is a data file not an application. Just like windows associations when you click on a file.xls your not executing file.xls but actually excel file.xls. The same is true when you click on a filename.rpm. The actual application that starts when you click on the rpm file is running on your local computer not the share.

http://en.wikipedia.org/wiki/RPM_Package_Manager

jcky · 09-11-2009, 07:19 PM

Hi michaelk,
What you meant was that the rpm package was not a binary file? If it was, then why I could execute it with noexec option? Thanks for your help!

michaelk · 09-11-2009, 07:37 PM

Not all binary files are executable. Here is another example, a windows word document is a binary file. When you click on it the actual program that starts and runs is word not the file.doc. Once again, its not the rpm file that is running.

FYI an RPM is a collection of files not all binary.

jcky · 09-11-2009, 07:44 PM

Hi Michaelk,
I understood your meaning that the rpm package was managed by rpm. When you wanted to install the rpm package, actually you ran rpm but not rpm binary package. Was I right? So with noexec options, it would not take effect.
Then I had another question. How can I verify the noexec option which did work? In other words, how could I make the experiment succsessful?
Thanks for your help!

michaelk · 09-11-2009, 08:08 PM

You got it. Create a simple bash script and try to run it from the server.

jcky · 09-11-2009, 08:10 PM

Thanks!

jcky · 09-12-2009, 02:47 AM

I tried a script made by bash language with noexec option when the shared directory was mounted. But I could exectue the script with right permission (x access).
So I really got confused.
Who could help me

r3sistance · 09-12-2009, 05:44 AM

how did you start the script? did you start the script, did you try to call on the script directly or did you use the sh command? Also can you confirm the filesystem has actually been remounted since you made the change to fstab or the machine rebooted.

jcky · 09-12-2009, 06:26 PM

Quote:

Originally Posted by r3sistance

how did you start the script? did you start the script, did you try to call on the script directly or did you use the sh command? Also can you confirm the filesystem has actually been remounted since you made the change to fstab or the machine rebooted.

I did run the script by sh command. But it really could work! Also I used mount command to check the mount status which was noexec.
So strange...

jcky · 09-13-2009, 09:31 PM

Who could help me????