Bugtraq mailing list archives
Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability
From: Wojciech Purczynski <cliph () isec pl>
Date: Wed, 15 Aug 2007 21:09:48 +0200 (CEST)
This doesn't change anything in what I said previously. If the sender's EUID or RUID equals to any of SUID or RUID of the victim or the sender process is root, the sender can send any signal to the victim; if none of those conditions are met, it obviously can't, no matter how and what signal it sends. For details look at check_kill_permission() and group_send_sig_info() in kernel/signal.c and reparent_thread() in kernel/exit.c in the kernel source tree (version 2.6.22).
Dan, could you take a closer look at what setuid(0) does? In the beggining of setuid manual page you can read that: setuid sets the effective user ID of the current process. If the effective userid of the caller is root, the real and saved user ID's are also set. In this case check_kill_permission() returns -EPERM for unprivileged parent.
Current thread:
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability, (continued)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Glynn Clements (Aug 16)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 17)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Glynn Clements (Aug 17)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 17)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Glynn Clements (Aug 20)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 20)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Nicolas Rachinsky (Aug 17)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 17)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 15)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Wojciech Purczynski (Aug 15)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 15)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Wojciech Purczynski (Aug 15)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 15)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Wojciech Purczynski (Aug 16)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Dan Yefimov (Aug 16)
- Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability Wojciech Purczynski (Aug 15)