Re: Error running socklog Klog service
George Georgalis <[email protected]>
| Newsgroups | gmane.comp.misc.pape.general |
|---|---|
| Message-ID | <[email protected]> |
On Sun, Apr 04, 2004 at 12:35:38PM +0200, Thomas Schwinge wrote: > >The socklog-klog run script first opens a file descriptor as root, then >drops permissions to an unprivileged user, and starts reading kernel >messages from the filedescriptor. This technique works fine with normal >filesystems. > >Unfortunately the implementation of the proc filesystem in the 2.6.x >linux kernels makes open() a noop, and checks permissions in read(). So >the newer linux kernels force the application reading from /proc/kmsg to >run under root privileges. > >See linux-2.6.1/fs/proc/kmsg.c and linux-2.6.1/kernel/printk.c, function >do_syslog(). Thanks for this useful info! Is there any doc on the implementation? I (still, 2.6.5) don't see mention in Documentation/ Is it of any value? Seems like too theoretical abstract threat to me.... // George -- George Georgalis, Architect and administrator, Linux services. IXOYE http://www.galis.org/george cell:646-331-2027 mailto:[email protected] Key fingerprint = 5415 2738 61CF 6AE1 E9A7 9EF0 0186 503B 9831 1631