Bugtraq mailing list archives
Re: COSEINC Linux Advisory #1: Linux Kernel Parent Process Death Signal Vulnerability
From: Dan Yefimov <dan () ns15 lightwave net ru>
Date: Wed, 15 Aug 2007 16:46:28 +0400 (MSD)
On Tue, 14 Aug 2007, Wojciech Purczynski wrote:
Small correction - I forgot to add setuid(0) ;) PARENT CHILD ---------------------------------------------------------------- fork() prctl(PR_SET_PDEATHSIG) execve("/bin/setuid-binary") setuid(0) exit()'ed or killed child receives NO signal this time PARENT CHILD ---------------------------------------------------------------- fork() prctl(PR_SET_PDEATHSIG) execve("/bin/setuid-binary") setuid(0) execve("/bin/setuid-binary") exit()'ed or killed privileged process receives the signal
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). -- Sincerely Your, Dan.
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 Dan Yefimov (Aug 16)
- 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)