>Number: 166921 >Category: misc >Synopsis: Use after free in dtrace(1) error handling >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Fri Apr 13 21:40:06 UTC 2012 >Closed-Date: >Last-Modified: >Originator: Ryan Stone >Release: 8-STABLE >Organization: >Environment: >Description: If I run dtrace(1) under valgrind (memcheck) and hit the "no probes matched" case, I sometimes see dtrace segfault. It would seem that one thread in dtrace frees memory while the other is still accessing it. If that memory is subsequently re-allocated dtrace crashes.
Running dtrace with MALLOC_OPTIONS=AJ would probably reproduce this easily. I think that one sample invocation was something like dtrace -p <pid> -n 'pid$target:libc*:malloc:entry' (see reqst00307862 for the fact that this doesn't match a probe in the first place. I think that this has the necessary syscalls implemented to run dtrace under valgrind: https://bitbucket.org/rysto32/valgrind-freebsd >How-To-Repeat: >Fix: >Release-Note: >Audit-Trail: >Unformatted: _______________________________________________ freebsd-bugs@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-bugs To unsubscribe, send any mail to "freebsd-bugs-unsubscr...@freebsd.org"
