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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE26CC001E0 for ; Mon, 23 Oct 2023 11:02:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233024AbjJWLCn (ORCPT ); Mon, 23 Oct 2023 07:02:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230468AbjJWLCm (ORCPT ); Mon, 23 Oct 2023 07:02:42 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69B6BD7B for ; Mon, 23 Oct 2023 04:02:40 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5C2EC433C7; Mon, 23 Oct 2023 11:02:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698058960; bh=ryLnOMc2Vf+xbT9dhk4gNE0e74JhcSF5vs1FBrZrmys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vpgm5r/fLOcFzjKyORGvIOK2S0uJgfyPc+pn0LP1kHKYbQ8AdpqG3XbP5lGL+mT5z MTav5THiKFmKhM7sDY7PGY0Iipe+AknguAHnySC0Edlif8Gi7OZui83XymWqiIF5JZ 53KeJuWvgvukSbuq7T3KZ7rkbNwiHZv9P4MifxSs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tom Dohrmann , Joerg Roedel , "Borislav Petkov (AMD)" , stable@kernel.org Subject: [PATCH 6.5 017/241] x86/sev: Check IOBM for IOIO exceptions from user-space Date: Mon, 23 Oct 2023 12:53:23 +0200 Message-ID: <20231023104834.343059094@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104833.832874523@linuxfoundation.org> References: <20231023104833.832874523@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joerg Roedel Upstream commit: b9cb9c45583b911e0db71d09caa6b56469eb2bdf Check the IO permission bitmap (if present) before emulating IOIO #VC exceptions for user-space. These permissions are checked by hardware already before the #VC is raised, but due to the VC-handler decoding race it needs to be checked again in software. Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions") Reported-by: Tom Dohrmann Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov (AMD) Tested-by: Tom Dohrmann Cc: Signed-off-by: Greg Kroah-Hartman --- arch/x86/boot/compressed/sev.c | 5 +++++ arch/x86/kernel/sev-shared.c | 22 +++++++++++++++------- arch/x86/kernel/sev.c | 27 +++++++++++++++++++++++++++ 3 files changed, 47 insertions(+), 7 deletions(-) --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -103,6 +103,11 @@ static enum es_result vc_read_mem(struct return ES_OK; } +static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size) +{ + return ES_OK; +} + #undef __init #define __init --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -696,6 +696,9 @@ static enum es_result vc_insn_string_wri static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo) { struct insn *insn = &ctxt->insn; + size_t size; + u64 port; + *exitinfo = 0; switch (insn->opcode.bytes[0]) { @@ -704,7 +707,7 @@ static enum es_result vc_ioio_exitinfo(s case 0x6d: *exitinfo |= IOIO_TYPE_INS; *exitinfo |= IOIO_SEG_ES; - *exitinfo |= (ctxt->regs->dx & 0xffff) << 16; + port = ctxt->regs->dx & 0xffff; break; /* OUTS opcodes */ @@ -712,41 +715,43 @@ static enum es_result vc_ioio_exitinfo(s case 0x6f: *exitinfo |= IOIO_TYPE_OUTS; *exitinfo |= IOIO_SEG_DS; - *exitinfo |= (ctxt->regs->dx & 0xffff) << 16; + port = ctxt->regs->dx & 0xffff; break; /* IN immediate opcodes */ case 0xe4: case 0xe5: *exitinfo |= IOIO_TYPE_IN; - *exitinfo |= (u8)insn->immediate.value << 16; + port = (u8)insn->immediate.value & 0xffff; break; /* OUT immediate opcodes */ case 0xe6: case 0xe7: *exitinfo |= IOIO_TYPE_OUT; - *exitinfo |= (u8)insn->immediate.value << 16; + port = (u8)insn->immediate.value & 0xffff; break; /* IN register opcodes */ case 0xec: case 0xed: *exitinfo |= IOIO_TYPE_IN; - *exitinfo |= (ctxt->regs->dx & 0xffff) << 16; + port = ctxt->regs->dx & 0xffff; break; /* OUT register opcodes */ case 0xee: case 0xef: *exitinfo |= IOIO_TYPE_OUT; - *exitinfo |= (ctxt->regs->dx & 0xffff) << 16; + port = ctxt->regs->dx & 0xffff; break; default: return ES_DECODE_FAILED; } + *exitinfo |= port << 16; + switch (insn->opcode.bytes[0]) { case 0x6c: case 0x6e: @@ -756,12 +761,15 @@ static enum es_result vc_ioio_exitinfo(s case 0xee: /* Single byte opcodes */ *exitinfo |= IOIO_DATA_8; + size = 1; break; default: /* Length determined by instruction parsing */ *exitinfo |= (insn->opnd_bytes == 2) ? IOIO_DATA_16 : IOIO_DATA_32; + size = (insn->opnd_bytes == 2) ? 2 : 4; } + switch (insn->addr_bytes) { case 2: *exitinfo |= IOIO_ADDR_16; @@ -777,7 +785,7 @@ static enum es_result vc_ioio_exitinfo(s if (insn_has_rep_prefix(insn)) *exitinfo |= IOIO_REP; - return ES_OK; + return vc_ioio_check(ctxt, (u16)port, size); } static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt) --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -524,6 +524,33 @@ static enum es_result vc_slow_virt_to_ph return ES_OK; } +static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size) +{ + BUG_ON(size > 4); + + if (user_mode(ctxt->regs)) { + struct thread_struct *t = ¤t->thread; + struct io_bitmap *iobm = t->io_bitmap; + size_t idx; + + if (!iobm) + goto fault; + + for (idx = port; idx < port + size; ++idx) { + if (test_bit(idx, iobm->bitmap)) + goto fault; + } + } + + return ES_OK; + +fault: + ctxt->fi.vector = X86_TRAP_GP; + ctxt->fi.error_code = 0; + + return ES_EXCEPTION; +} + /* Include code shared with pre-decompression boot stage */ #include "sev-shared.c"