Re: situation with signals

From: Al Viro
Date: Wed Oct 27 2010 - 19:30:29 EST


On Wed, Oct 27, 2010 at 06:51:12PM -0400, Chris Metcalf wrote:

> > BTW, is everything in your pt_regs safe to modify?
>
> What an interesting observation. :-) In fact, it would be possible to
> overwrite the privilege level (the ex1 register) from within the signal
> handler and then return to run arbitrary code at kernel PL. I'll fix it.

Then you need to be careful with that in your ptrace as well (POKEUSR and
SETREGS).
--
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/