Red Hat Bugzilla – Bug 162951
ssh fails if uid == 0 and gid != 0
Last modified: 2007-11-30 17:07:19 EST
Description of problem:
ssh fails if it is executed when uid is root and gid is non-root:
[root@test7 ~]# newgrp admin
[root@test7 ~]# id
[root@test7 ~]# ssh localhost
permanently_set_uid: was able to restore old [e]gid
Version-Release number of selected component (if applicable):
[root@test7 ~]# rpm -q openssh
This is fixed in openssh-4.1. This patch should fix it:
--- uidswap.c.orig Mon Jul 11 15:31:49 2005
+++ uidswap.c Mon Jul 11 15:33:52 2005
@@ -200,8 +200,8 @@
fatal("setuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
- /* Try restoration of GID if changed (test clearing of saved gid) */
- if (old_gid != pw->pw_gid &&
+ /* Try restoration of GID if changed and running non-root (test clearing
of saved gid) */
+ if (old_gid != pw->pw_gid && pw->pw_uid != 0 &&
(setgid(old_gid) != -1 || setegid(old_gid) != -1))
fatal("%s: was able to restore old [e]gid", __func__);
> This patch should fix it:
Yep, it does.
Known bug. Fix is already accepted.
> Known bug.
If it's known, please provide a reference. The bug seems to be unknown to RH's
It was reported internally so the bug report isn't visible.
I'm sorry if you took my answer as discouraging you from reporting the bug - it
wasn't meant so. I just wanted to state that the fix is already in works.
> I just wanted to state that the fix is already in works.
I'm curious as to why your internal bug reports (when not security sensite, at
least) aren't visible in Bugzilla.
FTR, the fix is here:
* Wed Apr 20 2005 Tomas Mraz <firstname.lastname@example.org> 3.9p1-8.RHEL4.5
- don't deadlock on exit with multiple X forwarded channels (#152432)
- allow ssh-ing from root account with nondefault group (#155220)