[lkml]   [2001]   [Jan]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC] prevention of syscalls from writable segments, breaking bug exploits

> It is known that most remote exploits use the fact that stacks are
> executable (in i386, at least).
> On Linux, they use INT 80 system calls to execute functions in the kernel
> as root, when the stack is smashed as a result of a buffer overflow bug in
> various server software.
> This preliminary, small patch prevents execution of system calls which
> were executed from a writable segment. It was tested and seems to work,
> without breaking anything. It also reports of such calls by using
> printk.


So exploit needs to call libc function to do dirty work for it. Not so
big deal.

Okay, it might do a trick and deter script kiddies; still it is even
weaker then non-executable stack patches.

I'm "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:52    [W:0.115 / U:2.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site