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View Full Version : [ubuntu] remote logging bug? (syslogd="-r")



configt
September 24th, 2009, 07:31 AM
Once I enable remote logging (/etc/default/syslogd syslogd="-r"), my desktop starts to be behave very strange (hangs on commands). I traced the problem using strace and ltrace. Once I disable remote logging (/etc/default/syslogd syslogd="") the problem is resolved. I am not DOS'ing myself, I just have one Cisco router sending about 5 messages per minute.

There is no indication in the logs as to why this happens. If it was not for the fact that I realized the issue was reproducible whenever using sudo, or trying to login, or gksudo, etc., anything to do with authentication, I never would have realized the relationship between my syslogd configuration and the symptoms.

Here is what I found and how I found it:

After I change /etc/default/syslogd 'SYSLOGD="-r"', remote logging from my Cisco works, BUT, the system would hang on many commands like simply logging in, or using sudo:

1) sudo -s (or su to root)
2) strace sudo ls
..
..
socket(PF_FILE, 0x80002 /* SOCK_??? */, 0) = 4
connect(4, {sa_family=AF_FILE, path="/dev/log"...}, 110) = 0 sendto(4, "<85>Sep 21 11:53:05 sudo: userna"..., 96, MSG_NOSIGNAL, NULL, 0) = 9

(hangs.... doesn't get past the above line for several minutes)
..
..


3) ltrace sudo ls
..
..
openlog("sudo", 0, 80) = <void>
__vsnprintf_chk(0x7fff9ca54a60, 961, 1, 961, 0x41350a) = 70
__syslog_chk(5, 1, 0x41352d, 0x7fff9ca54a60, 0x736c2f6e69622f3d) = 0x2490af0

(hangs... doesn't get past the above line for several minutes)
..
..


Once I change back to /etc/default/syslogd 'SYSLOGD=""'

Everything is fine again.


2.6.28-15-generic #49-Ubuntu SMP Tue Aug 18 19:25:34 UTC 2009 x86_64 GNU/Linux


Does anyone else have this problem? Or better yet, an explanation and reasonable solution?

Thank you.