From patchwork Wed Sep 28 08:14:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 1683816 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4MctPl6qvdz1yqH for ; Wed, 28 Sep 2022 20:43:23 +1000 (AEST) Received: from localhost ([::1]:50810 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1odUXB-0004jQ-Lu for incoming@patchwork.ozlabs.org; Wed, 28 Sep 2022 06:43:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33296) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1odSE4-00085y-Hc for qemu-devel@nongnu.org; Wed, 28 Sep 2022 04:15:28 -0400 Received: from mout.kundenserver.de ([217.72.192.75]:54657) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1odSE1-00089H-BL for qemu-devel@nongnu.org; Wed, 28 Sep 2022 04:15:27 -0400 Received: from quad ([82.142.8.70]) by mrelayeu.kundenserver.de (mreue108 [212.227.15.183]) with ESMTPSA (Nemesis) id 1M8QJq-1oZ4VE0ZZA-004T2F; Wed, 28 Sep 2022 10:15:20 +0200 From: Laurent Vivier To: qemu-devel@nongnu.org Cc: Jameson Nash , Laurent Vivier Subject: [PULL 02/38] linux-user: fix readlinkat handling with magic exe symlink Date: Wed, 28 Sep 2022 10:14:41 +0200 Message-Id: <20220928081517.734954-3-laurent@vivier.eu> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220928081517.734954-1-laurent@vivier.eu> References: <20220928081517.734954-1-laurent@vivier.eu> MIME-Version: 1.0 X-Provags-ID: V03:K1:dKIcFdxvcq8+kkyyuZxnYokDGGDmh9Fl8qSNLx43uBQuAaavcZP cmA30rrindKYENiBa3xlhcWR0rco314nS8M37XJ67Bmu6TFXdadZSxCmHGkpUcZgmI5OFkM F0rmD3B8SaWqidmZUc0XvuPooZXpD2TyxASXUTXTDWaKFSPS7YRLmWtodieHhHPSRnhWSNg s4Rok00VSQWny/ejxVcVQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:euF2N9/6ybc=:rdWjt5tBdJCNSCQ/cDzDmA ST+EYqHtwMZSL7MDz1cUdjw2VDO8gDkzvxLuZHZKVHCx875w7cuGsdV+XKlVqE1GEA12+rl38 jJ61Eno9+fnfn2DFxrAKCG1g2eGtJZkVv9XnCpC6+KFF+tutns59m5Tf6mM1CGPEFiyWmoT9t g/UjxCq/XJoeoblDk9f9s167OmayWj1cEgBo0MttkbYTxJESW2Hmawe1+xgv7RN2FTp35IL2M RL1UlcenwB8AA+gO2tRgX9UaNPVKUV25MFp1AZ20soLLTKgvKxxakoGI60I5S1Me+2Oe0jkff 9BqivrNFeTxT4nvrfgVHpdjN9jFhTWDPI7nsQbUpv9O8MxrHQb24UUgVmbN7vld090pElu2zC Lc1T8TDMgaa4c+5ZMIV25NczyJgZptXuBa0x38/YUwaOXcAeadiZx+JrmbCK8LWjjJ7chHFxf GU2VHJbN2Cu6lJ9jMrrXx8Z/oSX9oBDa4Btf2Pxx9hyMF/am6xTHVmhju/f6QorUvvEO0XimL iz6al9aW9HjFAHS4tehPIgwKCNai/LPMTAb5+w+W9xXa+M59dpuF24cTctj7iu4mb93WkRO6z 9ivqR1ARAo4olzhenYFY2rOYiZaMuonEpMog/1hv/IwIR7umgfu+9yrTHIHmvSVAwEozTFARX 5nwq7QM0JP7/CN5NMEckb8CzM2sTBwHoQ4jWknUCZJ/ce4A7LV483e7C8HdZguKfnonCiHKJO oRdZKXf3JA/dqclR/EG6TyTSxpPbIZv6regdO9Uk/X5Y3C5WQxTjzVAGNx2is667092HIhn67 jxuCccw Received-SPF: none client-ip=217.72.192.75; envelope-from=laurent@vivier.eu; helo=mout.kundenserver.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Jameson Nash Exactly the same as f17f4989fa193fa8279474c5462289a3cfe69aea before was for readlink. I suppose this was simply missed at the time. Signed-off-by: Jameson Nash Reviewed-by: Laurent Vivier Message-Id: <20220808190727.875155-1-vtjnash@gmail.com> Signed-off-by: Laurent Vivier --- linux-user/syscall.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index f4091212027c..abf82bab2a18 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -9912,11 +9912,22 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1, p2 = lock_user(VERIFY_WRITE, arg3, arg4, 0); if (!p || !p2) { ret = -TARGET_EFAULT; + } else if (!arg4) { + /* Short circuit this for the magic exe check. */ + ret = -TARGET_EINVAL; } else if (is_proc_myself((const char *)p, "exe")) { char real[PATH_MAX], *temp; temp = realpath(exec_path, real); - ret = temp == NULL ? get_errno(-1) : strlen(real) ; - snprintf((char *)p2, arg4, "%s", real); + /* Return value is # of bytes that we wrote to the buffer. */ + if (temp == NULL) { + ret = get_errno(-1); + } else { + /* Don't worry about sign mismatch as earlier mapping + * logic would have thrown a bad address error. */ + ret = MIN(strlen(real), arg4); + /* We cannot NUL terminate the string. */ + memcpy(p2, real, ret); + } } else { ret = get_errno(readlinkat(arg1, path(p), p2, arg4)); }