Red Hat Bugzilla – Bug 4328
bug in glibc inet/rexec.c breaks rexec(3) and rexec(1)
Last modified: 2008-05-01 11:37:51 EDT
rexec(3) should prompt the user for the logname/password if
it's not supplied by the caller, if it's not in the
environment and if it's not in $HOME/.netrc.
The problem is in glibc's inet/rexec.c. It's passing a nil
pointer into write() and dropping core.
rexec(3) _should_ be calling getuser() and getpass() prior
to doing that write().
I've tried to explain this to Ulrich but the message isn't
getting through. Perhaps you guys will have more luck.
# rm $HOME/.netrc
# rexec -a localhost date
Memory fault - core dumped
This appears to be a glibc problem.
yes, it is a glibc issue. Please see the bug-glibc mailing list
discussion "rexec, rexec() and ruserpass()" at
http://sourceware.cygnus.com/ml/bug-glibc/1999-07/ for the full story.
Note also the memory leak which I have identified.
Ulrich tells me that he'll be looking at this issue RSN, but that was
a couple of weeks back.
It is really a debate whether we can change the current behavior in
glibc 2.1. I'd be inclined to say no, bacuse this type of change does
not necessarily fits the definition of a bug fix because it leads to a
I'll make sure that this will get fixed in glibc 2.2, but for 2.1.x
series I'd rather not change it.
This is not a matter of changed functionality or of changing the
Every other rexec(2) in the world prompts the user if the credentials
are not available. However glibc's rexec(2) will dereference a nil
pointer and drops core.
It's a bug.
*** Bug 9715 has been marked as a duplicate of this bug. ***
I can't fix the glibc segfault, but rexec in rsh-0.16-10 now prompts
for password (and exits rather than segfaulting).
assign to jakub