Red Hat Bugzilla – Bug 2318
rexec(3) and in.rexecd implement different protocols.
Last modified: 2008-05-01 11:37:49 EDT
Firstly, in.rexec in RedHat 5.2 seems to have problems with the pam securetty entry. If you change auth required to auth sufficient, then there is a chance of in.rexec not failing. However... the real reason for this bug report is: If the final argument to rexec(3) is set to 0, then the rexec library call, and the corresponding in.rexec demon work apprently OK. If the final argument to rexec(3) is given as a pointer to a socket descriptor, in.rexec hangs and never logs in... it seems to be waiting for more data for somewhere. Help please! -- ange@hplb.hpl.hp.com --
*** This bug has been marked as a duplicate of 1696 ***
*** Bug 2909 has been marked as a duplicate of this bug. *** It seems that in.rexecd is buggy and hangs, it can be reproduced on a base Red Hat 6.0 box with a simple rexec -l user -p pass localhost date Doing an strace on it, we see that the rexec client sends the port number as the first "argument": write(3, "1716\0", 5) = 5 and waits for the socket to be created accept(4, <unfinished ...> while the rexec daemon reads the second argument (user) *before* creating the socket... ------- Additional Comments From jbj@redhat.com 05/18/99 12:26 ------- As a workaround, add -a to the rexec command line. ------- Additional Comments From jbj@redhat.com 05/18/99 12:27 ------- As a workaround, add -a to the rexec command line.
The workaround sent (-a) doesn't seem to work for me: # rexec -a -l root -p rootpass mybox date mybox.cern.ch: Success rexec: Error in rexec system call: Success
Fixed in.rexecd to repair damage to the rexec protocol when the last argument to rexec is supplied. The port is sent to the server which then connects back to the client after which the client supplies user, password, and command. This is the behavior implemented on Solaris (by trial) and on FreeBSD (by examining sources). OpenBSD has an rexecd that is broke the same way that netkit was broke.
*** Bug 3093 has been marked as a duplicate of this bug. *** Redhat is apparently not using the latest netkit. The latest netkit includes a patch that I contributed that fixes rexecd. As soon as I figure out how to submit that patch, I will send it to you.