From nobody Thu Apr 3 19:32:28 2025 X-Original-To: dev-commits-src-branches@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4ZTBhX5DQxz5sLwg; Thu, 03 Apr 2025 19:32:28 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R10" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4ZTBhX3cRFz3Sd2; Thu, 03 Apr 2025 19:32:28 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1743708748; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=nIon7UWWWgCIERESHUKZy6sOWE1Gf+p+LMwqeYdX6dY=; b=FCdQA/tEWlD1tlbe804HeGujjDpRILekEG+qYo9cQrF8wyy06NvW7QfYqKK8wDqxcTq45g C8VeWF6bHPx0LEOH5yXT+yqm83X+U3SH/mQyff6b/dSHmi3ql6mpsuYRVmg4EQaGTiSSIr 6vLFa4dWlwGU2ubSd9NRnRUDx9o5oVJVzyEZhQ+2v3DRFXE3QK3y29xmaaQTucseZktYP0 f10IF3+gEabuggAMWhfgTyOOqXNty0DHYQIy1lN573sO0uM4xFUOpBMFwzyA0eiyp4df1+ 9vIDriB21Kk/+6LwYm21nIcC0MZMC3DdpWNwt45RrSiaXpF9J7CfTii4etd5UQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1743708748; a=rsa-sha256; cv=none; b=GtLzgbC710XJ4VelLt5uZq7H7gNjqBtfJD2ffnyzUjSYgEDUyE/Piwnhx/nok9ruX3nWkV aYaTF2HqAwXym8Y55Wfjq8sAOhMDqY0cVbSxsrnQObQ4rINs6sPtd0zxfOp2mN3EvQbE4h +f54rb1HWrE5PxsDZWiUW6mzVfgMuvk2kySBvG5lqYHJqpqgPjiC8IP+THF5mtgXTELO2Z DqJXMWx6TJG4R/1Ne3/Vzx7LRNpkoqvDNU3rCCAAfMQs5OUrYmuo3rMFhUnWOrgYRIkLlm QonWVYKvW00DJd+eBlvKA1gv46gOqvauEf1xWehr/qVPZZvL0ejuZ7u1HsCWqA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1743708748; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=nIon7UWWWgCIERESHUKZy6sOWE1Gf+p+LMwqeYdX6dY=; b=nt8xlfiUHP4VSWNMEbuzMAbOafeEiQtx0Oy0ehdt6q4Vabiy/XxjfMJrtgL3uBq3yhsYP8 rOzPEgSnL2mEsDueSCo5CBx6vQqiAUU34ak0MGKLZe192zmDgxE9hW/WyjL1gbx37mn7R4 duMG4C5jHBILSe9/ULJdAajJ46ZTeXJBEWaFEUIdybHy0ukY4QR/7qaWg5xmebDAIH7evA AyC1wb2ZAQHPPPq/wpEaONs/IEz+sTUvUIQBh89ckLn8aFXivj+y2N+Wm7XrsgLoZexz2G 3gnW28L6CB6qPq/G0Zssd7nFtWEAS6aTg5JrDntnXM2W0+WyXsBdpQNbVEwG1w== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4ZTBhX3CxlzkW; Thu, 03 Apr 2025 19:32:28 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 533JWS8R040535; Thu, 3 Apr 2025 19:32:28 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 533JWSFJ040532; Thu, 3 Apr 2025 19:32:28 GMT (envelope-from git) Date: Thu, 3 Apr 2025 19:32:28 GMT Message-Id: <202504031932.533JWSFJ040532@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Olivier Certner Subject: git: 68c46c41a7f8 - stable/14 - mdo(1): Use setcred() to change credentials List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: olce X-Git-Repository: src X-Git-Refname: refs/heads/stable/14 X-Git-Reftype: branch X-Git-Commit: 68c46c41a7f875b245325e94e994fda1bd0b3056 Auto-Submitted: auto-generated The branch stable/14 has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=68c46c41a7f875b245325e94e994fda1bd0b3056 commit 68c46c41a7f875b245325e94e994fda1bd0b3056 Author: Olivier Certner AuthorDate: 2024-07-29 14:24:08 +0000 Commit: Olivier Certner CommitDate: 2025-04-03 19:31:05 +0000 mdo(1): Use setcred() to change credentials As this is the only system call that MAC/do currently supports, and the only one that really can be for transitions involving simultaneous changes of user and group IDs. Reviewed by: bapt Approved by: markj (mentor) Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D47621 (cherry picked from commit e395e354823b690ba19ecc8e3688bacec6f67ad3) --- usr.bin/mdo/mdo.c | 42 +++++++++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 7 deletions(-) diff --git a/usr.bin/mdo/mdo.c b/usr.bin/mdo/mdo.c index 22e2838daa08..8435fc17f26f 100644 --- a/usr.bin/mdo/mdo.c +++ b/usr.bin/mdo/mdo.c @@ -5,6 +5,7 @@ */ #include +#include #include #include @@ -27,6 +28,8 @@ main(int argc, char **argv) { struct passwd *pw; const char *username = "root"; + struct setcred wcred = SETCRED_INITIALIZER; + u_int setcred_flags = 0; bool uidonly = false; int ch; @@ -50,20 +53,45 @@ main(int argc, char **argv) const char *errp = NULL; uid_t uid = strtonum(username, 0, UID_MAX, &errp); if (errp != NULL) - err(EXIT_FAILURE, "%s", errp); + err(EXIT_FAILURE, "invalid user ID '%s'", + username); pw = getpwuid(uid); } if (pw == NULL) err(EXIT_FAILURE, "invalid username '%s'", username); } + + wcred.sc_uid = wcred.sc_ruid = wcred.sc_svuid = pw->pw_uid; + setcred_flags |= SETCREDF_UID | SETCREDF_RUID | SETCREDF_SVUID; + if (!uidonly) { - if (initgroups(pw->pw_name, pw->pw_gid) == -1) - err(EXIT_FAILURE, "failed to call initgroups"); - if (setgid(pw->pw_gid) == -1) - err(EXIT_FAILURE, "failed to call setgid"); + /* + * If there are too many groups specified for some UID, setting + * the groups will fail. We preserve this condition by + * allocating one more group slot than allowed, as + * getgrouplist() itself is just some getter function and thus + * doesn't (and shouldn't) check the limit, and to allow + * setcred() to actually check for overflow. + */ + const long ngroups_alloc = sysconf(_SC_NGROUPS_MAX) + 2; + gid_t *const groups = malloc(sizeof(*groups) * ngroups_alloc); + int ngroups = ngroups_alloc; + + if (groups == NULL) + err(EXIT_FAILURE, "cannot allocate memory for groups"); + + getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups); + + wcred.sc_gid = wcred.sc_rgid = wcred.sc_svgid = pw->pw_gid; + wcred.sc_supp_groups = groups + 1; + wcred.sc_supp_groups_nb = ngroups - 1; + setcred_flags |= SETCREDF_GID | SETCREDF_RGID | SETCREDF_SVGID | + SETCREDF_SUPP_GROUPS; } - if (setuid(pw->pw_uid) == -1) - err(EXIT_FAILURE, "failed to call setuid"); + + if (setcred(setcred_flags, &wcred, sizeof(wcred)) != 0) + err(EXIT_FAILURE, "calling setcred() failed"); + if (*argv == NULL) { const char *sh = getenv("SHELL"); if (sh == NULL)