[PATCH 4.5 006/101] bpf/verifier: reject invalid LD_ABS | BPF_DW instruction

From	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups	linux.kernel
Subject	[PATCH 4.5 006/101] bpf/verifier: reject invalid LD_ABS \| BPF_DW instruction
Date	2016-05-17 03:30 +0200
Message-ID	<rzBZF-6iF-39@gated-at.bofh.it> (permalink)
References	<rzBZD-6iF-3@gated-at.bofh.it>
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4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alexei Starovoitov <ast@fb.com>

[ Upstream commit d82bccc69041a51f7b7b9b4a36db0772f4cdba21 ]

verifier must check for reserved size bits in instruction opcode and
reject BPF_LD | BPF_ABS | BPF_DW and BPF_LD | BPF_IND | BPF_DW instructions,
otherwise interpreter will WARN_RATELIMIT on them during execution.

Fixes: ddd872bc3098 ("bpf: verifier: add checks for BPF_ABS | BPF_IND instructions")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 kernel/bpf/verifier.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1348,6 +1348,7 @@ static int check_ld_abs(struct verifier_
 	}
 
 	if (insn->dst_reg != BPF_REG_0 || insn->off != 0 ||
+	    BPF_SIZE(insn->code) == BPF_DW ||
 	    (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) {
 		verbose("BPF_LD_ABS uses reserved fields\n");
 		return -EINVAL;

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[PATCH 4.5 006/101] bpf/verifier: reject invalid LD_ABS | BPF_DW instruction Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-05-17 03:30 +0200

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