From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8D22C76191 for ; Mon, 15 Jul 2019 13:57:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A22272182B for ; Mon, 15 Jul 2019 13:57:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563199062; bh=EF9gBj3ANZWN266C3vBbahB5lj/m+UxlSc0GzWSqjbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rQ6rnGwbNe7YpoQ18Wmb3ieZqoKAPkeT788F/rOnj+Dy7PIbODLBEDaZ5xq1cSb7e KZWhebn32/noWSNvBwn/8PHdjtm4LF9aURfep9OVN1GGKlphwsXDIlcQKFlpv9NL2i qXdAJYsnkZ/SwL4P1/kItMy5rgigQxOySQCq3kRI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732988AbfGON5l (ORCPT ); Mon, 15 Jul 2019 09:57:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:35728 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732973AbfGON5j (ORCPT ); Mon, 15 Jul 2019 09:57:39 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A3F57212F5; Mon, 15 Jul 2019 13:57:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563199058; bh=EF9gBj3ANZWN266C3vBbahB5lj/m+UxlSc0GzWSqjbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fxp4nKeXITN6ZuLakDZbkrk0SXVFffQ03W6q3HiOJL/5hb78rzU4pS/ejAa8dl5Zm 7UV/W3BTATDIVZAio0x4N7eG6K8lKDeolAsODAJ1a2G40DEke23JnBNAATEeiJ2ViD 162t7dsG5JbAqg2lYXN3ZZr6HtaPrGJ+JRq93Xa0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jiong Wang , Yauheni Kaliuta , Jakub Kicinski , Quentin Monnet , Song Liu , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 177/249] bpf: fix BPF_ALU32 | BPF_ARSH on BE arches Date: Mon, 15 Jul 2019 09:45:42 -0400 Message-Id: <20190715134655.4076-177-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715134655.4076-1-sashal@kernel.org> References: <20190715134655.4076-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiong Wang [ Upstream commit 75672dda27bd00109a84cd975c17949ad9c45663 ] Yauheni reported the following code do not work correctly on BE arches: ALU_ARSH_X: DST = (u64) (u32) ((*(s32 *) &DST) >> SRC); CONT; ALU_ARSH_K: DST = (u64) (u32) ((*(s32 *) &DST) >> IMM); CONT; and are causing failure of test_verifier test 'arsh32 on imm 2' on BE arches. The code is taking address and interpreting memory directly, so is not endianness neutral. We should instead perform standard C type casting on the variable. A u64 to s32 conversion will drop the high 32-bit and reserve the low 32-bit as signed integer, this is all we want. Fixes: 2dc6b100f928 ("bpf: interpreter support BPF_ALU | BPF_ARSH") Reported-by: Yauheni Kaliuta Reviewed-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Jiong Wang Acked-by: Song Liu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- kernel/bpf/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 080e2bb644cc..f2148db91439 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1364,10 +1364,10 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) insn++; CONT; ALU_ARSH_X: - DST = (u64) (u32) ((*(s32 *) &DST) >> SRC); + DST = (u64) (u32) (((s32) DST) >> SRC); CONT; ALU_ARSH_K: - DST = (u64) (u32) ((*(s32 *) &DST) >> IMM); + DST = (u64) (u32) (((s32) DST) >> IMM); CONT; ALU64_ARSH_X: (*(s64 *) &DST) >>= SRC; -- 2.20.1