lkml.org 
[lkml]   [1998]   [Sep]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] (please check) Potential security fix for i386/kernel/ptrace.c


On Sun, 20 Sep 1998, Jamie Lokier wrote:
>
> The problem is that a user may be able to a hardware breakpoint in the
> kernel address range; who knows what affect that may have. This may
> crash the kernel or simply leak information; either thing is not good.

It should actually be safe. The debug trap handler is careful to not
aquire any locks (ie no deadlock situations), and should alwasy ignore
events from kernel space.

The patch looks fine regardless, but I want to have a robust system, and
that does mean that even if somebody can trigger a debug trap in the
kernel (easy to do by just having a read() system call write over
something you want to get the trap on in user mode) then the kernel should
not really have to care anyway.

So it might actually be valid to rmeove the test altogether. I'll think
about it.

Linus


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:44    [W:0.036 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site