From da4465506dbcfd5162b628be28365b1e3a3d3126 Mon Sep 17 00:00:00 2001 From: Alan Somers Date: Fri, 3 Aug 2018 01:37:00 +0000 Subject: [PATCH] Fix LOCAL_PEERCRED with socketpair(2) Enable the LOCAL_PEERCRED socket option for unix domain stream sockets created with socketpair(2). Previously, it only worked with unix domain stream sockets created with socket(2)/listen(2)/connect(2)/accept(2). PR: 176419 Reported by: Nicholas Wilson MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D16350 --- sys/kern/uipc_syscalls.c | 11 ++++ sys/kern/uipc_usrreq.c | 39 ++++++++------ sys/sys/unpcb.h | 9 ++++ tests/sys/kern/Makefile | 3 +- tests/sys/kern/unix_socketpair_test.c | 76 +++++++++++++++++++++++++++ 5 files changed, 120 insertions(+), 18 deletions(-) create mode 100644 tests/sys/kern/unix_socketpair_test.c diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c index 2e05de78037e..fde98d1ac66e 100644 --- a/sys/kern/uipc_syscalls.c +++ b/sys/kern/uipc_syscalls.c @@ -58,6 +58,8 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include +#include #ifdef KTRACE #include #endif @@ -612,6 +614,15 @@ kern_socketpair(struct thread *td, int domain, int type, int protocol, error = soconnect2(so2, so1); if (error != 0) goto free4; + } else if (so1->so_proto->pr_flags & PR_CONNREQUIRED) { + struct unpcb *unp, *unp2; + unp = sotounpcb(so1); + unp2 = sotounpcb(so2); + /* + * No need to lock the unps, because the sockets are brand-new. + * No other threads can be using them yet + */ + unp_copy_peercred(td, unp, unp2, unp); } finit(fp1, FREAD | FWRITE | fflag, DTYPE_SOCKET, fp1->f_data, &socketops); diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c index ac93ea1b9c4e..77a9d9a5a830 100644 --- a/sys/kern/uipc_usrreq.c +++ b/sys/kern/uipc_usrreq.c @@ -1609,24 +1609,8 @@ unp_connectat(int fd, struct socket *so, struct sockaddr *nam, sa = NULL; } - /* - * The connector's (client's) credentials are copied from its - * process structure at the time of connect() (which is now). - */ - cru2x(td->td_ucred, &unp3->unp_peercred); - unp3->unp_flags |= UNP_HAVEPC; + unp_copy_peercred(td, unp3, unp, unp2); - /* - * The receiver's (server's) credentials are copied from the - * unp_peercred member of socket on which the former called - * listen(); uipc_listen() cached that process's credentials - * at that time so we can use them now. - */ - memcpy(&unp->unp_peercred, &unp2->unp_peercred, - sizeof(unp->unp_peercred)); - unp->unp_flags |= UNP_HAVEPC; - if (unp2->unp_flags & UNP_WANTCRED) - unp3->unp_flags |= UNP_WANTCRED; UNP_PCB_UNLOCK(unp2); unp2 = unp3; unp_pcb_owned_lock2(unp2, unp, freed); @@ -1665,6 +1649,27 @@ unp_connectat(int fd, struct socket *so, struct sockaddr *nam, return (error); } +/* + * Set socket peer credentials at connection time. + * + * The client's PCB credentials are copied from its process structure. The + * server's PCB credentials are copied from the socket on which it called + * listen(2). uipc_listen cached that process's credentials at the time. + */ +void +unp_copy_peercred(struct thread *td, struct unpcb *client_unp, + struct unpcb *server_unp, struct unpcb *listen_unp) +{ + cru2x(td->td_ucred, &client_unp->unp_peercred); + client_unp->unp_flags |= UNP_HAVEPC; + + memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, + sizeof(server_unp->unp_peercred)); + server_unp->unp_flags |= UNP_HAVEPC; + if (listen_unp->unp_flags & UNP_WANTCRED) + client_unp->unp_flags |= UNP_WANTCRED; +} + static int unp_connect2(struct socket *so, struct socket *so2, int req) { diff --git a/sys/sys/unpcb.h b/sys/sys/unpcb.h index 7363e5e47d03..9583da646d81 100644 --- a/sys/sys/unpcb.h +++ b/sys/sys/unpcb.h @@ -166,4 +166,13 @@ struct xunpgen { } __aligned(8);; #endif /* _SYS_SOCKETVAR_H_ */ +#if defined(_KERNEL) +struct thread; + +/* In uipc_userreq.c */ +void +unp_copy_peercred(struct thread *td, struct unpcb *client_unp, + struct unpcb *server_unp, struct unpcb *listen_unp); +#endif + #endif /* _SYS_UNPCB_H_ */ diff --git a/tests/sys/kern/Makefile b/tests/sys/kern/Makefile index 079d494b11d5..0ab4a70a41b8 100644 --- a/tests/sys/kern/Makefile +++ b/tests/sys/kern/Makefile @@ -12,9 +12,10 @@ TEST_METADATA.ptrace_test+= timeout="15" ATF_TESTS_C+= reaper PLAIN_TESTS_C+= subr_unit_test ATF_TESTS_C+= sys_getrandom -ATF_TESTS_C+= unix_seqpacket_test ATF_TESTS_C+= unix_passfd_test +ATF_TESTS_C+= unix_seqpacket_test TEST_METADATA.unix_seqpacket_test+= timeout="15" +ATF_TESTS_C+= unix_socketpair_test ATF_TESTS_C+= waitpid_nohang ATF_TESTS_C+= pdeathsig diff --git a/tests/sys/kern/unix_socketpair_test.c b/tests/sys/kern/unix_socketpair_test.c new file mode 100644 index 000000000000..2bcd6b7a8778 --- /dev/null +++ b/tests/sys/kern/unix_socketpair_test.c @@ -0,0 +1,76 @@ +/*- + * Copyright (c) 2018 Alan Somers + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include +__FBSDID("$FreeBSD$"); + +#include +#include +#include +#include +#include +#include + +#include + +#include + +/* getpeereid(3) should work with stream sockets created via socketpair(2) */ +ATF_TC_WITHOUT_HEAD(getpeereid); +ATF_TC_BODY(getpeereid, tc) +{ + int sv[2]; + int s; + uid_t real_euid, euid; + gid_t real_egid, egid; + + real_euid = geteuid(); + real_egid = getegid(); + + s = socketpair(PF_LOCAL, SOCK_STREAM, 0, sv); + ATF_CHECK_EQ(0, s); + ATF_CHECK(sv[0] >= 0); + ATF_CHECK(sv[1] >= 0); + ATF_CHECK(sv[0] != sv[1]); + + ATF_REQUIRE_EQ(0, getpeereid(sv[0], &euid, &egid)); + ATF_CHECK_EQ(real_euid, euid); + ATF_CHECK_EQ(real_egid, egid); + + ATF_REQUIRE_EQ(0, getpeereid(sv[1], &euid, &egid)); + ATF_CHECK_EQ(real_euid, euid); + ATF_CHECK_EQ(real_egid, egid); + + close(sv[0]); + close(sv[1]); +} + + +ATF_TP_ADD_TCS(tp) +{ + ATF_TP_ADD_TC(tp, getpeereid); + + return atf_no_error(); +}