From patchwork Tue Jul 23 10:05:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivian Wang X-Patchwork-Id: 1963717 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=dram.page header.i=@dram.page header.a=rsa-sha256 header.s=mail header.b=lvcrS51r; dkim-atps=neutral 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=patchwork.ozlabs.org) 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 4WSt9g5KKVz1yZw for ; Tue, 23 Jul 2024 20:07:19 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sWCPf-0001NT-Js; Tue, 23 Jul 2024 06:06:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sWCPe-0001Lt-LY for qemu-devel@nongnu.org; Tue, 23 Jul 2024 06:06:30 -0400 Received: from kuriko.dram.page ([65.108.252.55]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sWCPZ-0007Jd-F2 for qemu-devel@nongnu.org; Tue, 23 Jul 2024 06:06:28 -0400 From: Vivian Wang DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dram.page; s=mail; t=1721729182; bh=qMID2xczG5B6sBH1FwIwhYTdVvpjThT0Ch5GCuMOoA4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lvcrS51rhDwPrWiN0zx4MbeGIlBZVqVBM3OpORa6JzPeZzc0BsESED3mY+R4YOyf+ Ua/ek9bmWrxvo+gCBT2YKAmH1mFDK+87gR1tMtjB41dppwkGSxMF1U+HQDAw2JFHkh e9tZ3byfKQrJ2jdImOGCFt1+fg1MQDa0+KtxDh14= To: qemu-devel@nongnu.org Cc: Vivian Wang , Richard Henderson , Laurent Vivier , Richard Henderson Subject: [PATCH v2 2/2] linux-user/main: Check errno when getting AT_EXECFD Date: Tue, 23 Jul 2024 18:05:45 +0800 Message-ID: <20240723100545.405476-3-uwu@dram.page> In-Reply-To: <20240723100545.405476-1-uwu@dram.page> References: <20240723100545.405476-1-uwu@dram.page> MIME-Version: 1.0 Received-SPF: pass client-ip=65.108.252.55; envelope-from=uwu@dram.page; helo=kuriko.dram.page X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-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-bounces+incoming=patchwork.ozlabs.org@nongnu.org It's possible for AT_EXECFD to end up with a valid value of 0. Check errno when using qemu_getauxval instead of return value to handle this case. Not handling this case leads to a confusing condition where the executable ends up as fd 0, i.e. stdin. Signed-off-by: Vivian Wang Reviewed-by: Richard Henderson Fixes: 0b959cf5e4cc ("linux-user: Use qemu_getauxval for AT_EXECFD") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2448 --- linux-user/main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/linux-user/main.c b/linux-user/main.c index 7d3cf45fa9..8143a0d4b0 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -755,8 +755,9 @@ int main(int argc, char **argv, char **envp) /* * Manage binfmt-misc open-binary flag */ + errno = 0; execfd = qemu_getauxval(AT_EXECFD); - if (execfd == 0) { + if (errno != 0) { execfd = open(exec_path, O_RDONLY); if (execfd < 0) { printf("Error while loading %s: %s\n", exec_path, strerror(errno));