[syslog-ng] Critical hang while opening tty

Jean-Baptiste Quenot jbq at caraldi.com
Fri Jun 5 13:22:51 CEST 2009

Hi there,

I'm using syslog-ng 2.0.9-4.1 on Ubuntu 9.04.  In the configuration
file, emergency messages are configured to be logged to all ttys.
Sometimes syslog-ng blocks the whole system while opening /dev/ttyS0:

# pgrep -f syslog-ng
# strace -f -p 3172
Process 3172 attached - interrupt to quit
open("/dev/ttyS0", O_WRONLY|O_NOCTTY|O_APPEND

I'm surprised because I saw the same bug report, and this was supposed
to be fixed in Ubuntu's 2.0.9-1 version as stated in the changelog at
See http://changelogs.ubuntu.com/changelogs/pool/universe/s/syslog-ng/syslog-ng_2.0.9-4.1/changelog

The changelog says:

syslog-ng (2.0.9-1) unstable; urgency=low

  * New upstream version. (Closes: #397650, #447105)

This corresponds to this bug:

syslog-ng hangs writing to /dev/ttyN

I notice the bug is fixed in syslog-ng:

Is there maybe another call to tty open() that was not covered by alarm()?

The issue happens on several machines, but I don't know what triggers
this.  Reloading syslog-ng fixes the problem.

Thanks in advance,
Jean-Baptiste Quenot

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