Re: [PATCH] kernel: make /proc/kallsyms mode 400 to reduce ease ofattacking
From: Ingo Molnar
Date: Thu Nov 18 2010 - 02:49:09 EST
* Kyle McMartin <kyle@xxxxxxxxxxx> wrote:
> On Tue, Nov 16, 2010 at 11:46:03AM +0100, Marcus Meissner wrote:
> > Target of this starter patch and follow ups is removing any kind of
> > kernel space address information leak from the kernel.
> Er. Should probably hit /proc/modules while you're at it.
Agreed. A few other kernel address things that should be hidden are:
Gives out kernel addresses and is a partial /proc/kallsyms table in essence. This
got introduced recently. Useful to attackers.
Then there's a handful of physical address leaks - those are less useful but useful
in some situations:
Gives some idea about the physical layout of the machine and can give information
about the location of certain physical devices as well. Limited but nonzero utility
Can gives out the physical address of a device. Limited but nonzero utility to
Shows physical addresses. Limited but nonzero utility to attackers.
Plus there's some really limited fractional pieces of information - again, of
nonzero utility to attackers:
Shows the sizes of a few kernel functions in networking code. Very limited but
nonzero utility to attackers.
Shows the sizes of a few kernel functions. Very limited but nonzero utility to
Potentially useful to attackers.
There's probably a few more i missed.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/