oss-sec mailing list archives
Re: CVE request - kernel: DoS on x86_64
From: Eugene Teo <eugene () redhat com>
Date: Thu, 04 Feb 2010 13:09:09 +0800
On 02/04/2010 10:28 AM, dann frazier wrote:
On Mon, Feb 01, 2010 at 01:09:12PM +0800, Eugene Teo wrote:Reported by Mathias Krause. The problem seams to be located in fs/binfmt_elf.c:load_elf_binary(). It calls SET_PERSONALITY() prior checking that the ELF interpreter is available. This in turn makes the previously 32 bit process a 64 bit one which would be fine if execve() would succeed. But after the SET_PERSONALITY() the open_exec() call fails (because it cannot find the interpreter) and execve() almost instantly returns with an error. If you now look at /proc/PID/maps you'll see, that it has the vsyscall page mapped which shouldn't be. But the process is not dead yet, it's still running. By now generating a segmentation fault and in turn trying to generate a core dump the kernel just dies. Steps to Reproduce: 1. Enable core dumps 2. Start an 32 bit program that tries to execve() an 64 bit program 3. The 64 bit program cannot be started by the kernel because it can't find the interpreter, i.e. execve returns with an error 4. Generate a segmentation fault 5. panic Upstream commit: http://git.kernel.org/linus/221af7f87b97431e3ee21ce4b0e77d5411cf1549Thanks Eugene. Also note this fix for a regression in the above: http://git.kernel.org/linus/7ab02af428c2d312c0cf8fb0b01cc1eb21131a3d
Ben Hutchings reported (via stable review list) that the fix did not work for him. Will monitor the list if there are other follow-ups.
Thanks, Eugene -- Eugene Teo / Red Hat Security Response Team
Current thread:
- CVE request - kernel: DoS on x86_64 Eugene Teo (Jan 31)
- Re: CVE request - kernel: DoS on x86_64 dann frazier (Feb 03)
- Re: CVE request - kernel: DoS on x86_64 Eugene Teo (Feb 03)
- Re: CVE request - kernel: DoS on x86_64 dann frazier (Feb 04)
- Re: CVE request - kernel: DoS on x86_64 Eugene Teo (Feb 17)
- Re: CVE request - kernel: DoS on x86_64 Eugene Teo (Feb 03)
- Re: CVE request - kernel: DoS on x86_64 dann frazier (Feb 03)
- <Possible follow-ups>
- Re: CVE request - kernel: DoS on x86_64 Josh Bressers (Feb 01)