From owner-svn-src-all@freebsd.org Wed Oct 28 22:12:47 2020 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id B682C451833; Wed, 28 Oct 2020 22:12:47 +0000 (UTC) (envelope-from kib@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 "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4CM2rH4RPyz4dvF; Wed, 28 Oct 2020 22:12:47 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 7B885231B5; Wed, 28 Oct 2020 22:12:47 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 09SMClPB080205; Wed, 28 Oct 2020 22:12:47 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 09SMClWb080204; Wed, 28 Oct 2020 22:12:47 GMT (envelope-from kib@FreeBSD.org) Message-Id: <202010282212.09SMClWb080204@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Wed, 28 Oct 2020 22:12:47 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r367120 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: kib X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 367120 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Oct 2020 22:12:47 -0000 Author: kib Date: Wed Oct 28 22:12:47 2020 New Revision: 367120 URL: https://svnweb.freebsd.org/changeset/base/367120 Log: Check for process group change in tty_wait_background(). The calling process's process group can change between PROC_UNLOCK(p) and PGRP_LOCK(pg) in tty_wait_background(), e.g. by a setpgid() call from another process. If that happens, the signal is not sent to the calling process, even if the prior checks determine that one should be sent. Re-check that the process group hasn't changed after acquiring the pgrp lock, and if it has, redo the checks. PR: 250701 Submitted by: Jakub Piecuch MFC after: 2 weeks Modified: head/sys/kern/tty.c Modified: head/sys/kern/tty.c ============================================================================== --- head/sys/kern/tty.c Wed Oct 28 21:18:04 2020 (r367119) +++ head/sys/kern/tty.c Wed Oct 28 22:12:47 2020 (r367120) @@ -474,6 +474,19 @@ tty_wait_background(struct tty *tp, struct thread *td, sig = 0; } PGRP_LOCK(pg); + + /* + * pg may no longer be our process group. + * Re-check after locking process group. + */ + PROC_LOCK(p); + if (p->p_pgrp != pg) { + PROC_UNLOCK(p); + PGRP_UNLOCK(pg); + continue; + } + + PROC_UNLOCK(p); pgsignal(pg, ksi.ksi_signo, 1, &ksi); PGRP_UNLOCK(pg);