From patchwork Fri Oct 1 21:14:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Naveen N. Rao" X-Patchwork-Id: 12531687 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBEC1C4332F for ; Fri, 1 Oct 2021 21:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7CFA619EE for ; Fri, 1 Oct 2021 21:15:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229568AbhJAVRe (ORCPT ); Fri, 1 Oct 2021 17:17:34 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:15162 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230112AbhJAVRe (ORCPT ); Fri, 1 Oct 2021 17:17:34 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 191KfuZe011175; Fri, 1 Oct 2021 17:15:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=e7Ddj3dVgziHQJ2nzn00PX1MwCevHba3PBXMOqUd1A4=; b=Af+DSSBHzFsf5moCYRPjOUF1Cs4js5LslxR/B+6hCUq8BJMCBkL4wxwyuZ7qKK+/mnz6 ix6rG7g8/DMFC/fhKM9EkCpbEOgtmxHfQaKvAQUf7mOk/tVRbiaubK0EvJC8f6g4ZE1e tD28/uTyL0CrwtdUD4aZuWK6Mh4mYhWIMyNwzVIK+XZavQuryZlmH9WLU1WgW6NL5xEm 3eBWYWbNpoGZlJtXXWzBV9kAAnUO2OB3Xbp70dykp+sAB7PVZal9Hswc0goilij+Ie44 3fLXVcMUpI2WQu0xjt0iRtgiW0Xf839z/B4ScVXac+1fBdg5Wu81pIzRcc+SuXiZ2EOd 8A== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3be9kcrnqh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 01 Oct 2021 17:15:31 -0400 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 191KhV96018223; Fri, 1 Oct 2021 17:15:30 -0400 Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0a-001b2d01.pphosted.com with ESMTP id 3be9kcrnq5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 01 Oct 2021 17:15:30 -0400 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 191L86YD030322; Fri, 1 Oct 2021 21:15:29 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma06ams.nl.ibm.com with ESMTP id 3b9u1kj4s0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 01 Oct 2021 21:15:28 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 191LAFFn55050540 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 1 Oct 2021 21:10:15 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 71FA54C05E; Fri, 1 Oct 2021 21:15:26 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 985604C04E; Fri, 1 Oct 2021 21:15:23 +0000 (GMT) Received: from naverao1-tp.ibm.com (unknown [9.43.54.98]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 1 Oct 2021 21:15:23 +0000 (GMT) From: "Naveen N. Rao" To: Michael Ellerman , Nicholas Piggin , Daniel Borkmann , Alexei Starovoitov , Christophe Leroy , Johan Almbladh Cc: , Subject: [PATCH 2/9] powerpc/bpf: Validate branch ranges Date: Sat, 2 Oct 2021 02:44:48 +0530 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: h5UdAEsozLDLFRSXhnlX78nmtjP4nbA5 X-Proofpoint-GUID: UUD6-byFPYpY0F9zWNdxtyp-r7CeHWot X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-10-01_05,2021-10-01_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 phishscore=0 mlxscore=0 malwarescore=0 impostorscore=0 mlxlogscore=999 suspectscore=0 spamscore=0 priorityscore=1501 clxscore=1015 lowpriorityscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2110010147 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add checks to ensure that we never emit branch instructions with truncated branch offsets. Suggested-by: Michael Ellerman Signed-off-by: Naveen N. Rao Acked-by: Song Liu Acked-by: Johan Almbladh Tested-by: Johan Almbladh --- arch/powerpc/net/bpf_jit.h | 26 ++++++++++++++++++++------ arch/powerpc/net/bpf_jit_comp.c | 6 +++++- arch/powerpc/net/bpf_jit_comp32.c | 8 ++++++-- arch/powerpc/net/bpf_jit_comp64.c | 8 ++++++-- 4 files changed, 37 insertions(+), 11 deletions(-) diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index 935ea95b66359e..7e9b978b768ed9 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -24,16 +24,30 @@ #define EMIT(instr) PLANT_INSTR(image, ctx->idx, instr) /* Long jump; (unconditional 'branch') */ -#define PPC_JMP(dest) EMIT(PPC_INST_BRANCH | \ - (((dest) - (ctx->idx * 4)) & 0x03fffffc)) +#define PPC_JMP(dest) \ + do { \ + long offset = (long)(dest) - (ctx->idx * 4); \ + if (!is_offset_in_branch_range(offset)) { \ + pr_err_ratelimited("Branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ + return -ERANGE; \ + } \ + EMIT(PPC_INST_BRANCH | (offset & 0x03fffffc)); \ + } while (0) + /* blr; (unconditional 'branch' with link) to absolute address */ #define PPC_BL_ABS(dest) EMIT(PPC_INST_BL | \ (((dest) - (unsigned long)(image + ctx->idx)) & 0x03fffffc)) /* "cond" here covers BO:BI fields. */ -#define PPC_BCC_SHORT(cond, dest) EMIT(PPC_INST_BRANCH_COND | \ - (((cond) & 0x3ff) << 16) | \ - (((dest) - (ctx->idx * 4)) & \ - 0xfffc)) +#define PPC_BCC_SHORT(cond, dest) \ + do { \ + long offset = (long)(dest) - (ctx->idx * 4); \ + if (!is_offset_in_cond_branch_range(offset)) { \ + pr_err_ratelimited("Conditional branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ + return -ERANGE; \ + } \ + EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc)); \ + } while (0) + /* Sign-extended 32-bit immediate load */ #define PPC_LI32(d, i) do { \ if ((int)(uintptr_t)(i) >= -32768 && \ diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index 53aefee3fe70be..fcbf7a917c566e 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -210,7 +210,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) /* Now build the prologue, body code & epilogue for real. */ cgctx.idx = 0; bpf_jit_build_prologue(code_base, &cgctx); - bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass); + if (bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass)) { + bpf_jit_binary_free(bpf_hdr); + fp = org_fp; + goto out_addrs; + } bpf_jit_build_epilogue(code_base, &cgctx); if (bpf_jit_enable > 1) diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index beb12cbc8c2994..a74d52204f8da2 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -200,7 +200,7 @@ void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 fun } } -static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) +static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) { /* * By now, the eBPF program has already setup parameters in r3-r6 @@ -261,7 +261,9 @@ static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 bpf_jit_emit_common_epilogue(image, ctx); EMIT(PPC_RAW_BCTR()); + /* out: */ + return 0; } /* Assemble the body code between the prologue & epilogue */ @@ -1090,7 +1092,9 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * */ case BPF_JMP | BPF_TAIL_CALL: ctx->seen |= SEEN_TAILCALL; - bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); + ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); + if (ret < 0) + return ret; break; default: diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index b87a63dba9c8fb..f06c62089b1457 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -206,7 +206,7 @@ void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 fun EMIT(PPC_RAW_BCTRL()); } -static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) +static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) { /* * By now, the eBPF program has already setup parameters in r3, r4 and r5 @@ -267,7 +267,9 @@ static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 bpf_jit_emit_common_epilogue(image, ctx); EMIT(PPC_RAW_BCTR()); + /* out: */ + return 0; } /* Assemble the body code between the prologue & epilogue */ @@ -993,7 +995,9 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * */ case BPF_JMP | BPF_TAIL_CALL: ctx->seen |= SEEN_TAILCALL; - bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); + ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); + if (ret < 0) + return ret; break; default: