Red Hat Bugzilla – Bug 56703
Using strace on smbd hangs kernel
Last modified: 2008-08-01 12:22:51 EDT
Description of problem:
Using strace on a running smbd process will cause the kernel to hang. (No
response to ping, no response to keyboard, no response to Ctrl-Alt-Del.)
Version-Release number of selected component (if applicable):
(But I only tried twice.)
Steps to Reproduce:
1. Run smbd
2. Pick a pid of of a child process to trace (ie. one running as a user,
not as root)
3. As root, strace -f <pid>, or strace -f <pid> -o <file>
Actual Results: The first time, this gave "eh? notify_parent with state
0?" (see kernel/signal.c:613 notify_parent in kernel 2.2.19-6.2.12),
followed by a hang. This log event did not make it to disk.
The second time, the kernel just hanged.
1) The machine on which this is running is a twin processor Pentium III
(Coppermine) 600MHz running the SMP kernel and the following modules:
nfsd, lockd, sunrpc, autofs, 3c59x, eepro100, st, raid5, raid1, aic7xxx.
2) At the time of the crashes, the machine was lightly loaded.
3) I have not tested with strace as a normal user, only as root, therefore
I don't know if this is a potential DoS. (At 30-40 minutes per reboot, I'm
keen on performing very many experiments!)
Thanks for the bug report. However, Red Hat no longer maintains this version of
the product. Please upgrade to the latest version and open a new bug if the problem
The Fedora Legacy project (http://fedoralegacy.org/) maintains some older releases,
and if you believe this bug is interesting to them, please report the problem in
the bug tracker at: http://bugzilla.fedora.us/