Re: [PATCH] bsdacct: switch credentials for writing to the accounting file

[David Howells <dhowells@redhat.com>]

Michal Schmidt <mschmidt@redhat.com> wrote:

> When process accounting is enabled, every exiting process writes a log
> to the account file. In addition, every once in a while one of the
> exiting processes checks whether there's enough free space for the log.
> 
> SELinux policy may or may not allow the exiting process to stat the fs.
> So unsuspecting processes start generating AVC denials just because
> someone enabled process accounting.
> 
> For these filesystem operations, the exiting process's credentials
> should be temporarily switched to that of the process which enabled
> accounting, because it's really that process who wanted to have the
> accounting information logged.
> 
> Signed-off-by: Michal Schmidt <mschmidt@redhat.com>

Do you really need to keep creds in acct?  Can you used acct->file->f_cred
instead?  Those are the credentials of the process that opened the file, so
acct->cred may be redundant.

Other than that, it looks reasonable.

David