From owner-dev-commits-src-all@freebsd.org Tue Jun 15 18:30:40 2021 Return-Path: Delivered-To: dev-commits-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 4BF246501EF; Tue, 15 Jun 2021 18:30:40 +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 "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4G4H1r1VJ0z4pNP; Tue, 15 Jun 2021 18:30:40 +0000 (UTC) (envelope-from git@FreeBSD.org) 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 1C8445316; Tue, 15 Jun 2021 18:30:40 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 15FIUenp053379; Tue, 15 Jun 2021 18:30:40 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 15FIUeOW053378; Tue, 15 Jun 2021 18:30:40 GMT (envelope-from git) Date: Tue, 15 Jun 2021 18:30:40 GMT Message-Id: <202106151830.15FIUeOW053378@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mariusz Zaborski Subject: git: 6c0a51837f4b - stable/11 - libcasper: fix descriptors numbers MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: oshogbo X-Git-Repository: src X-Git-Refname: refs/heads/stable/11 X-Git-Reftype: branch X-Git-Commit: 6c0a51837f4ba242ea723a887c3b6120d9335c8f Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Jun 2021 18:30:40 -0000 The branch stable/11 has been updated by oshogbo: URL: https://cgit.FreeBSD.org/src/commit/?id=6c0a51837f4ba242ea723a887c3b6120d9335c8f commit 6c0a51837f4ba242ea723a887c3b6120d9335c8f Author: Mariusz Zaborski AuthorDate: 2021-06-09 21:46:51 +0000 Commit: Mariusz Zaborski CommitDate: 2021-06-15 18:30:27 +0000 libcasper: fix descriptors numbers Casper services expect that the first 3 descriptors (stdin/stdout/stderr) will point to /dev/null. Which Casper will ensure later. The Casper services are forked from the original process. If the initial process closes one of those descriptors, Casper may reuse one of them for it on purpose. If this is the case, then renumarate the descriptors used by Casper to higher numbers. This is done already after the fork, so it doesn't break the parent process. PR: 255339 Reported by: Borja Marcos Tested by: jkim@ (cherry picked from commit aa310ebfba3d49a0b6b03a103b969731a8136a73) --- lib/libcasper/libcasper/libcasper_impl.c | 27 +++++++++++++++++++++++++++ lib/libcasper/libcasper/libcasper_impl.h | 1 + lib/libcasper/libcasper/service.c | 23 +++++++++++++---------- lib/libcasper/libcasper/zygote.c | 15 +++++++++------ 4 files changed, 50 insertions(+), 16 deletions(-) diff --git a/lib/libcasper/libcasper/libcasper_impl.c b/lib/libcasper/libcasper/libcasper_impl.c index 57d489943252..f58bd44d2039 100644 --- a/lib/libcasper/libcasper/libcasper_impl.c +++ b/lib/libcasper/libcasper/libcasper_impl.c @@ -30,8 +30,10 @@ * $FreeBSD$ */ +#include #include #include +#include #include #include "libcasper_impl.h" @@ -42,3 +44,28 @@ fd_is_valid(int fd) return (fcntl(fd, F_GETFL) != -1 || errno != EBADF); } + +void +fd_fix_environment(int *fdp) +{ + int nullfd, nfd; + + if (*fdp > STDERR_FILENO) + return; + + nullfd = open(_PATH_DEVNULL, O_RDWR); + if (nullfd == -1) + errx(1, "Unable to open %s", _PATH_DEVNULL); + + while (*fdp <= STDERR_FILENO) { + nfd = dup(*fdp); + if (nfd == -1) + errx(1, "Unable to secure fd"); + if (dup2(nullfd, *fdp) == -1) + errx(1, "Unable to secure fd"); + *fdp = nfd; + } + + close(nullfd); +} + diff --git a/lib/libcasper/libcasper/libcasper_impl.h b/lib/libcasper/libcasper/libcasper_impl.h index 89f244d0b87d..01dbd234e3ff 100644 --- a/lib/libcasper/libcasper/libcasper_impl.h +++ b/lib/libcasper/libcasper/libcasper_impl.h @@ -42,6 +42,7 @@ struct service; struct service_connection; bool fd_is_valid(int fd); +void fd_fix_environment(int *fdp); /* Private service functions. */ struct service *service_alloc(const char *name, diff --git a/lib/libcasper/libcasper/service.c b/lib/libcasper/libcasper/service.c index cc53d0d630ae..b3d2d2f05ea3 100644 --- a/lib/libcasper/libcasper/service.c +++ b/lib/libcasper/libcasper/service.c @@ -365,24 +365,27 @@ stdnull(void) } static void -service_clean(int sock, int procfd, uint64_t flags) +service_clean(int *sockp, int *procfdp, uint64_t flags) { int fd, maxfd, minfd; - assert(sock > STDERR_FILENO); - assert(procfd > STDERR_FILENO); - assert(sock != procfd); + fd_fix_environment(sockp); + fd_fix_environment(procfdp); + + assert(*sockp > STDERR_FILENO); + assert(*procfdp > STDERR_FILENO); + assert(*sockp != *procfdp); if ((flags & CASPER_SERVICE_STDIO) == 0) stdnull(); if ((flags & CASPER_SERVICE_FD) == 0) { - if (procfd > sock) { - maxfd = procfd; - minfd = sock; + if (*procfdp > *sockp) { + maxfd = *procfdp; + minfd = *sockp; } else { - maxfd = sock; - minfd = procfd; + maxfd = *sockp; + minfd = *procfdp; } for (fd = STDERR_FILENO + 1; fd < maxfd; fd++) { @@ -403,7 +406,7 @@ service_start(struct service *service, int sock, int procfd) assert(service != NULL); assert(service->s_magic == SERVICE_MAGIC); setproctitle("%s", service->s_name); - service_clean(sock, procfd, service->s_flags); + service_clean(&sock, &procfd, service->s_flags); if (service_connection_add(service, sock, NULL) == NULL) exit(1); diff --git a/lib/libcasper/libcasper/zygote.c b/lib/libcasper/libcasper/zygote.c index feeb1537af87..ef0032ddf58d 100644 --- a/lib/libcasper/libcasper/zygote.c +++ b/lib/libcasper/libcasper/zygote.c @@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$"); #include #include +#include "libcasper_impl.h" #include "zygote.h" /* Zygote info. */ @@ -88,7 +89,7 @@ zygote_clone(zygote_func_t *func, int *chanfdp, int *procfdp) * between sandbox and its owner. */ static void -zygote_main(int sock) +zygote_main(int *sockp) { int error, procfd; int chanfd[2]; @@ -96,12 +97,14 @@ zygote_main(int sock) zygote_func_t *func; pid_t pid; - assert(sock > STDERR_FILENO); + fd_fix_environment(sockp); + + assert(*sockp > STDERR_FILENO); setproctitle("zygote"); for (;;) { - nvlin = nvlist_recv(sock, 0); + nvlin = nvlist_recv(*sockp, 0); if (nvlin == NULL) { if (errno == ENOTCONN) { /* Casper exited. */ @@ -133,7 +136,7 @@ zygote_main(int sock) break; case 0: /* Child. */ - close(sock); + close(*sockp); close(chanfd[0]); func(chanfd[1]); /* NOTREACHED */ @@ -155,7 +158,7 @@ send: nvlist_move_descriptor(nvlout, "chanfd", chanfd[0]); nvlist_move_descriptor(nvlout, "procfd", procfd); } - (void)nvlist_send(sock, nvlout); + (void)nvlist_send(*sockp, nvlout); nvlist_destroy(nvlout); } /* NOTREACHED */ @@ -182,7 +185,7 @@ zygote_init(void) case 0: /* Child. */ close(sp[0]); - zygote_main(sp[1]); + zygote_main(&sp[1]); /* NOTREACHED */ abort(); default: