Red Hat Bugzilla – Bug 1268958
sudo - cmnd_no_wait can cause child processes to ignore SIGPIPE
Last modified: 2016-11-03 16:31:50 EDT
+++ This bug was initially created as a clone of Bug #1094548 +++
Description of problem:
The bug 1094548 appears to be present also on RHEL7.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Set "Defaults cmnd_no_wait" in /etc/sudoers
2. Run the following command all together:
$ sudo -k; sudo bash -c "yes | fold | head -n1"
Note: As mentioned below, the sudo -k is important to ensure there
is an out of date cache. 
Sudo ignores SIGPIPE somewhere in the authentication stack, perhaps
in src/tgetpass.c. Thus the command hangs.
The chain executed by sudo should not hang in these cases.
Created attachment 1155628 [details]
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.