On Mon, 11 Mar 2013 13:37:53 -0700 Kees Cook <[email protected]> wrote:
> ... > (pop toasting undone) > > Subject: signal: always clear sa_restorer on execve > > > > When the new signal handlers are set up, the location of sa_restorer is > > not cleared, leaking a parent process's address space location to > > children. This allows for a potential bypass of the parent's ASLR by > > examining the sa_restorer value returned when calling sigaction(). > > > > Based on what should be considered "secret" about addresses, it only > > matters across the exec not the fork (since the VMAs haven't changed until > > the exec). But since exec sets SIG_DFL and keeps sa_restorer, this is > > where it should be fixed. > > A note for backporters: you'll likely want to change > __ARCH_HAS_SA_RESTORER to SA_RESTORER, since the former was recently > introduced. If not, this will apply but not actually do any good. I added this to the changelog, but I fear people won't read it! Is there any clever way in which we can have one patch which will work OK in both old and new kernels? I can't think of one... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
