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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD88CC54EE9 for ; Tue, 20 Sep 2022 12:12:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7226694000E; Tue, 20 Sep 2022 08:12:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6D223940009; Tue, 20 Sep 2022 08:12:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 572B194000E; Tue, 20 Sep 2022 08:12:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 48232940009 for ; Tue, 20 Sep 2022 08:12:37 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 26F7FAB404 for ; Tue, 20 Sep 2022 12:12:37 +0000 (UTC) X-FDA: 79932351954.05.EB59804 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf19.hostedemail.com (Postfix) with ESMTP id AAD3A1A000D for ; Tue, 20 Sep 2022 12:12:34 +0000 (UTC) Received: from dggpeml500022.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MX0j12T20zpSyJ; Tue, 20 Sep 2022 20:09:41 +0800 (CST) Received: from dggpeml500008.china.huawei.com (7.185.36.147) by dggpeml500022.china.huawei.com (7.185.36.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 20 Sep 2022 20:12:29 +0800 Received: from huawei.com (10.67.175.34) by dggpeml500008.china.huawei.com (7.185.36.147) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 20 Sep 2022 20:12:28 +0800 From: Ren Zhijie To: , , CC: , , , Subject: [PATCH] exec: Force binary name when argv is empty Date: Tue, 20 Sep 2022 20:08:12 +0800 Message-ID: <20220920120812.231417-1-renzhijie2@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.175.34] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500008.china.huawei.com (7.185.36.147) X-CFilter-Loop: Reflected ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663675955; a=rsa-sha256; cv=none; b=znKJzSef27qpMUid2MP0uLUaz7iv7zkrUfsuYNczCEWZZ3u3jk4PUdGT3CgqNQY+m44mWl 6P09yDkfsLqrISE0zSGJAOo/xAF9/h6euVBpxkj8VMv0Qe6rDevmok3GkFfnfsbrAaiL9D YSKQ5htoNpTN1WF5j0/bTAz6AGPr8o4= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf19.hostedemail.com: domain of renzhijie2@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=renzhijie2@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663675955; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding:in-reply-to: references; bh=qdlwvUWahYx8GQhFT6VYH4j3U9Q1KrgZYyJky+A0zDk=; b=Xh5QqVyqwiH6PfRY2krdLF0CKZnKjZxsuJmnO7yhqXl+duRQWJ88rbQjYVlQlZFiBclH2n 1wAPzugBU7x7wOtN8Qtfc+Z3yMcVNS+4loLzK3myljWy5+Nz3fV2epcT5u7FNJvWG2Bk9M 1i+RoHKPXcSZLeX/nTDt0v/Gc/I6Li0= Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf19.hostedemail.com: domain of renzhijie2@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=renzhijie2@huawei.com X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: 6kcggjsuhj5hz4fjdntzmmxe1qdh5txs X-Rspamd-Queue-Id: AAD3A1A000D X-HE-Tag: 1663675954-701 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Hui Tang First run './execv-main execv-child', there is empty in 'COMMAND' column when run 'ps -u'. USER PID %CPU %MEM VSZ RSS TTY [...] TIME COMMAND root 368 0.3 0.0 4388 764 ttyS0 0:00 ./execv-main root 369 0.6 0.0 4520 812 ttyS0 0:00 The program 'execv-main' as follows: int main(int argc, char **argv) { char *execv_argv[] = {NULL}; pid_t pid = fork(); if (pid == 0) { execv(argv[1], execv_argv); } else if (pid > 0) { wait(NULL); } return 0; } So replace empty string ("") added with the name of binary when calling execve with a NULL argv. Fixes: dcd46d897adb ("exec: Force single empty string when argv is empty") Signed-off-by: Hui Tang --- fs/exec.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 939d76e23935..7d1909a89a57 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -494,8 +494,8 @@ static int bprm_stack_limits(struct linux_binprm *bprm) * signal to the parent that the child has run out of stack space. * Instead, calculate it here so it's possible to fail gracefully. * - * In the case of argc = 0, make sure there is space for adding a - * empty string (which will bump argc to 1), to ensure confused + * In the case of argc = 0, make sure there is space for adding + * bprm->filename (which will bump argc to 1), to ensure confused * userspace programs don't start processing from argv[1], thinking * argc can never be 0, to keep them from walking envp by accident. * See do_execveat_common(). @@ -1900,7 +1900,7 @@ static int do_execveat_common(int fd, struct filename *filename, retval = count(argv, MAX_ARG_STRINGS); if (retval == 0) - pr_warn_once("process '%s' launched '%s' with NULL argv: empty string added\n", + pr_warn_once("process '%s' launched '%s' with NULL argv: bprm->filename added\n", current->comm, bprm->filename); if (retval < 0) goto out_free; @@ -1929,13 +1929,13 @@ static int do_execveat_common(int fd, struct filename *filename, goto out_free; /* - * When argv is empty, add an empty string ("") as argv[0] to + * When argv is empty, add bprm->filename as argv[0] to * ensure confused userspace programs that start processing * from argv[1] won't end up walking envp. See also * bprm_stack_limits(). */ if (bprm->argc == 0) { - retval = copy_string_kernel("", bprm); + retval = copy_string_kernel(bprm->filename, bprm); if (retval < 0) goto out_free; bprm->argc = 1; -- 2.17.1