From e184a21b5ccc49f3e1c3160bc280a5995e933b04 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Wed, 6 Oct 2021 01:55:22 +0530 Subject: [PATCH] powerpc/bpf: Fix BPF_MOD when imm == 1 commit 8bbc9d822421d9ac8ff9ed26a3713c9afc69d6c8 upstream. Only ignore the operation if dividing by 1. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Signed-off-by: Naveen N. Rao Tested-by: Johan Almbladh Reviewed-by: Christophe Leroy Acked-by: Song Liu Acked-by: Johan Almbladh Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c674ca18c3046885602caebb326213731c675d06.1633464148.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/net/bpf_jit_comp64.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 0752967..a2750d6 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -415,8 +415,14 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ if (imm == 0) return -EINVAL; - else if (imm == 1) - goto bpf_alu32_trunc; + if (imm == 1) { + if (BPF_OP(code) == BPF_DIV) { + goto bpf_alu32_trunc; + } else { + EMIT(PPC_RAW_LI(dst_reg, 0)); + break; + } + } PPC_LI32(b2p[TMP_REG_1], imm); switch (BPF_CLASS(code)) { -- 2.7.4