From: Daniel Borkmann <daniel@iogearbox.net>
Date: Sat, 10 Jun 2017 22:50:43 +0000 (+0200)
Subject: bpf: reset id on spilled regs in clear_all_pkt_pointers
X-Git-Tag: microblaze-4.14-rc3~599^2~221^2~4
X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=36e24c003091a11ec847291c9a1d36d2ec92b155;p=linux-2.6-microblaze.git

bpf: reset id on spilled regs in clear_all_pkt_pointers

Right now, we don't reset the id of spilled registers in case of
clear_all_pkt_pointers(). Given pkt_pointers are highly likely to
contain an id, do so by reusing __mark_reg_unknown_value().

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d195d825515a..519a6144d3d3 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1346,8 +1346,8 @@ static void clear_all_pkt_pointers(struct bpf_verifier_env *env)
 		if (reg->type != PTR_TO_PACKET &&
 		    reg->type != PTR_TO_PACKET_END)
 			continue;
-		reg->type = UNKNOWN_VALUE;
-		reg->imm = 0;
+		__mark_reg_unknown_value(state->spilled_regs,
+					 i / BPF_REG_SIZE);
 	}
 }