linux-sg2042/arch/x86/net
Eric Dumazet 314beb9bca x86: bpf_jit_comp: secure bpf jit against spraying attacks
hpa bringed into my attention some security related issues
with BPF JIT on x86.

This patch makes sure the bpf generated code is marked read only,
as other kernel text sections.

It also splits the unused space (we vmalloc() and only use a fraction of
the page) in two parts, so that the generated bpf code not starts at a
known offset in the page, but a pseudo random one.

Refs:
http://mainisusuallyafunction.blogspot.com/2012/11/attacking-hardened-linux-systems-with.html

Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-19 23:55:41 -07:00
..
Makefile net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
bpf_jit.S bpf jit: Let the x86 jit handle negative offsets 2012-04-03 18:01:41 -04:00
bpf_jit_comp.c x86: bpf_jit_comp: secure bpf jit against spraying attacks 2013-05-19 23:55:41 -07:00