From: Daniel Borkmann <daniel@iogearbox.net>
Date: Sun, 11 Jun 2017 00:50:43 +0200
Subject: bpf: reset id on spilled regs in clear_all_pkt_pointers
Patch-mainline: v4.13-rc1
Git-commit: 36e24c003091a11ec847291c9a1d36d2ec92b155
References: bsc#1056787

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 kernel/bpf/verifier.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1358,8 +1358,8 @@ static void clear_all_pkt_pointers(struc
 		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);
 	}
 }