From nobody Wed May 28 01:19:27 2025 X-Original-To: dev-commits-src-main@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 4b6Wr01tBSz5wgjN; Wed, 28 May 2025 01:19:28 +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 "R11" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4b6Wqz6DH8z4LcS; Wed, 28 May 2025 01:19:27 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1748395167; 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=xsn4LNOmfPf0WxbckRKqE7iQcZ8cBLP10umNicoQw0I=; b=uCw4hsRJ/M2u9sUiYZmEvn6R9tsBfwB54F6SOOIXFphZ/8QEEbl/vjessNgFSJkXg8HCus FkkKYBI2/HM00/maJ8JqsEHDZ+ArdbAQWMiF8dwruqwZjXb6slIgbg6XTPGn6Vus68jp4i j2dtqpDRd4CzwTjxdBKRIWmQIAQlJBBTEs0yvEQ3X8SiAgVMwKzX6txms/mQx0CpTyxlJq mNs+PROCyItbKEq9okyczy4M4VFJVs2WjfkA2JsrOImM+FdQfzlt8fpYKgY1CqucQa7aus hjbHFaRxloHWqb2IF6mCB+7XixvNUJJmsZhULZ5INztUiaFJsnTgBasxRH+TDA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1748395167; a=rsa-sha256; cv=none; b=isxcQCkSANaDAnitkOJS1F8/JMzki7qjt5oCYs11Jr5z34Pka1ULjpKV3RAWcTb5PttNjm Oq5+PF7YA8+P2EF1EmwrLv/UNl/VjjD/edMI1UCPg0Q34Z8IU5bYHb5FOVCzfvjjlO8Lhq p6QV4BgDUHt6MLnTq7Zw9ddrVPoLwUf6oc4yQgtptYT5gn13DzxFSM21ToT/rGfb4hWDN7 +vzfexe1n+A1TxMuRvLl8tFNiMbcAsJDIOQl/0KH4xxkf1px31zDO8fTcW4TLFMH0u3TOC bbsO1/1H87wObjKQuUf81IzrokjgReLFsWfFDzZDQYzK+r7yDg23p0tTYyrOAw== 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=1748395167; 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=xsn4LNOmfPf0WxbckRKqE7iQcZ8cBLP10umNicoQw0I=; b=r3143/BGsSc5yK487/WpXIC5bnMoSp1ZgdmKzwNCJXavOcB/hA1Wwyfexqb3y0tBDMXjP1 BFudm5nc5+IFqRYO1cQZdaiOrfZCbjhFsI1MKen3Xvbt0GtUPX0//S0Y4J1Ed7mbFMiWeA UPXfK1knAYSg+Z0fqfxUppTdXpPjW0NtLfyoHKfDMRLjVqQ+8u/smLKly/VOwLg7RosYMd V2KYdT84/7OgZvj7cS86OyvdT25c9A6ZcKxAEoTfjUDCKsXNJXhBbZZR5o516g1o/UL2d5 Swn2+b4UeDBBVQpnt6EDejR3nJJweKWkj/8cHuxg09u7dQNgp9L/Y4vA3lhA7w== 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 4b6Wqz5Zdfz23T; Wed, 28 May 2025 01:19:27 +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 54S1JRH7031862; Wed, 28 May 2025 01:19:27 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 54S1JRpk031859; Wed, 28 May 2025 01:19:27 GMT (envelope-from git) Date: Wed, 28 May 2025 01:19:27 GMT Message-Id: <202505280119.54S1JRpk031859@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Kyle Evans Subject: git: 59fc4cda1bfa - main - kern: tty: refactor TIOCSTI privilege checks slightly List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kevans X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 59fc4cda1bfa712c46d407d1e83bdd5c63e6e0e3 Auto-Submitted: auto-generated The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=59fc4cda1bfa712c46d407d1e83bdd5c63e6e0e3 commit 59fc4cda1bfa712c46d407d1e83bdd5c63e6e0e3 Author: Kyle Evans AuthorDate: 2025-05-28 01:19:17 +0000 Commit: Kyle Evans CommitDate: 2025-05-28 01:19:17 +0000 kern: tty: refactor TIOCSTI privilege checks slightly This removes some repetition from it and makes the flow a little more obvious. Future work may find some way to add more constraints to the unprivileged path, add a security sysctl to disable it, or perhaps some combination of the two. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D50506 --- sys/kern/tty.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/sys/kern/tty.c b/sys/kern/tty.c index b1b3b268d0e9..47f9f25cec37 100644 --- a/sys/kern/tty.c +++ b/sys/kern/tty.c @@ -1643,6 +1643,24 @@ tty_set_winsize(struct tty *tp, const struct winsize *wsz) tty_signal_pgrp(tp, SIGWINCH); } +static int +tty_sti_check(struct tty *tp, int fflag, struct thread *td) +{ + /* Root can bypass all of our constraints. */ + if (priv_check(td, PRIV_TTY_STI) == 0) + return (0); + + /* Unprivileged users must have it opened for read. */ + if ((fflag & FREAD) == 0) + return (EPERM); + + /* It must also be their controlling tty. */ + if (!tty_is_ctty(tp, td->td_proc)) + return (EACCES); + + return (0); +} + static int tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td) @@ -1988,11 +2006,9 @@ tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, tty_info(tp); return (0); case TIOCSTI: - if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI)) - return (EPERM); - if (!tty_is_ctty(tp, td->td_proc) && - priv_check(td, PRIV_TTY_STI)) - return (EACCES); + error = tty_sti_check(tp, fflag, td); + if (error != 0) + return (error); ttydisc_rint(tp, *(char *)data, 0); ttydisc_rint_done(tp); return (0);