https://bugzilla.balabit.com/show_bug.cgi?id=8 Summary: syslog-ng hangs writing to /dev/ttyN Product: syslog-ng Version: 2.0.x Platform: PC URL: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=397650 OS/Version: Linux Status: NEW Severity: normal Priority: unspecified Component: syslog-ng AssignedTo: bazsi@balabit.hu ReportedBy: sasa@debian.org Type of the Report: bug Estimated Hours: 0.0 Created an attachment (id=4) --> (https://bugzilla.balabit.com/attachment.cgi?id=4) Patch to prevent hanging
From bugs.debian.org:
(This is the same problem reported against syslog-ng in Gentoo at https://bugs.gentoo.org/show_bug.cgi?id=154465 -- this contains a patch which fixes the problem with a similar approach to that taken in sysklogd.) When syslog-ng writes to a tty under Linux, for example as a result of a usertty directive, the write syscall to /dev/ttyN can ocassionally block indefinitely. One situation when this occurs is when the user has set XOFF (perhaps with Ctrl-S or Scroll Lock). Aside from the fact that this obvious prevents any further log messages from being written, /dev/log's buffer eventually fills up causing other programs to block writing to /dev/log. In extremis, this can render a machine inaccesible when ssh, etc., all block preventing access. Reproducible: Always Steps to Reproduce: 1. Check that there is a usertty("*") directive for (say) kern.emerg logs 2. Ensure syslog-ng is running 3. On console, press Scroll Lock 4. Log something, e.g. logger -p kern.emerg 'Foo'. 5. Repeat #4 many times; eventually it will hang trying to log -- Configure bugmail: https://bugzilla.balabit.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching all bug changes.