Date: Wed, 29 Apr 2026 14:49:27 +0000 Message-ID: <69f21a77.3a9f9.344b8d10@gitrepo.freebsd.org>
index | next in thread | raw e-mail
The branch releng/14.3 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=a872c32f389eb855f1a2caae69485c834c4c1d5c commit a872c32f389eb855f1a2caae69485c834c4c1d5c Author: Mariusz Zaborski <oshogbo@FreeBSD.org> AuthorDate: 2026-04-28 14:35:10 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2026-04-28 20:33:04 +0000 libnv: switch fd_wait() from select(2) to poll(2) The previous implementation used FD_SET() on a stack-allocated fd_set, which is an out-of-bounds write whenever the socket fd is >= FD_SETSIZE (1024). Approved by: so Security: FreeBSD-SA-26:16.libnv Security: CVE-2026-39457 Reported by: Joshua Rogers of AISLE Research Team (https://aisle.com/) Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D56689 --- lib/libnv/msgio.c | 12 +++---- lib/libnv/tests/nvlist_send_recv_test.c | 56 +++++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+), 6 deletions(-) diff --git a/lib/libnv/msgio.c b/lib/libnv/msgio.c index 002c626647d9..d972ced3c86c 100644 --- a/lib/libnv/msgio.c +++ b/lib/libnv/msgio.c @@ -33,10 +33,10 @@ #include <sys/cdefs.h> #include <sys/param.h> #include <sys/socket.h> -#include <sys/select.h> #include <errno.h> #include <fcntl.h> +#include <poll.h> #include <stdbool.h> #include <stdint.h> #include <stdlib.h> @@ -87,14 +87,14 @@ msghdr_add_fd(struct cmsghdr *cmsg, int fd) static void fd_wait(int fd, bool doread) { - fd_set fds; + struct pollfd pfd; PJDLOG_ASSERT(fd >= 0); - FD_ZERO(&fds); - FD_SET(fd, &fds); - (void)select(fd + 1, doread ? &fds : NULL, doread ? NULL : &fds, - NULL, NULL); + pfd.fd = fd; + pfd.events = doread ? POLLIN : POLLOUT; + pfd.revents = 0; + (void)poll(&pfd, 1, -1); } static int diff --git a/lib/libnv/tests/nvlist_send_recv_test.c b/lib/libnv/tests/nvlist_send_recv_test.c index cd97ccb6b9b9..c60428c79978 100644 --- a/lib/libnv/tests/nvlist_send_recv_test.c +++ b/lib/libnv/tests/nvlist_send_recv_test.c @@ -28,6 +28,8 @@ #include <sys/cdefs.h> #include <sys/param.h> +#include <sys/resource.h> +#include <sys/select.h> #include <sys/socket.h> #include <sys/sysctl.h> #include <sys/wait.h> @@ -534,6 +536,59 @@ ATF_TC_BODY(nvlist_send_recv__send_nvlist__stream, tc) nvlist_send_recv__send_nvlist(SOCK_STREAM); } +/* + * Regression test for fd_wait(): the previous select(2)-based implementation + * called FD_SET() unconditionally, which is an out-of-bounds stack write when + * the socket fd is >= FD_SETSIZE. Force the socketpair fds above FD_SETSIZE + * and verify a full nvlist round-trip still works. + */ +ATF_TC_WITHOUT_HEAD(nvlist_send_recv__highfd); +ATF_TC_BODY(nvlist_send_recv__highfd, tc) +{ + struct rlimit rl; + nvlist_t *nvl; + int socks[2], hi_send, hi_recv, status; + pid_t pid; + + hi_send = FD_SETSIZE + 5; + hi_recv = FD_SETSIZE + 6; + + rl.rlim_cur = rl.rlim_max = hi_recv + 1; + if (setrlimit(RLIMIT_NOFILE, &rl) != 0) + atf_tc_skip("cannot raise RLIMIT_NOFILE: %s", strerror(errno)); + + ATF_REQUIRE(socketpair(PF_UNIX, SOCK_STREAM, 0, socks) == 0); + ATF_REQUIRE(dup2(socks[0], hi_recv) == hi_recv); + ATF_REQUIRE(dup2(socks[1], hi_send) == hi_send); + (void)close(socks[0]); + (void)close(socks[1]); + + pid = fork(); + ATF_REQUIRE(pid >= 0); + if (pid == 0) { + /* Child: send. */ + (void)close(hi_recv); + nvl = nvlist_create(0); + nvlist_add_string(nvl, "key", "value"); + if (nvlist_send(hi_send, nvl) != 0) + err(EXIT_FAILURE, "nvlist_send"); + nvlist_destroy(nvl); + _exit(0); + } + + (void)close(hi_send); + nvl = nvlist_recv(hi_recv, 0); + ATF_REQUIRE(nvl != NULL); + ATF_REQUIRE(nvlist_error(nvl) == 0); + ATF_REQUIRE(nvlist_exists_string(nvl, "key")); + ATF_REQUIRE(strcmp(nvlist_get_string(nvl, "key"), "value") == 0); + nvlist_destroy(nvl); + + ATF_REQUIRE(waitpid(pid, &status, 0) == pid); + ATF_REQUIRE(status == 0); + (void)close(hi_recv); +} + ATF_TC_WITHOUT_HEAD(nvlist_send_recv__send_closed_fd__dgram); ATF_TC_BODY(nvlist_send_recv__send_closed_fd__dgram, tc) { @@ -737,6 +792,7 @@ ATF_TP_ADD_TCS(tp) ATF_TP_ADD_TC(tp, nvlist_send_recv__send_nvlist__dgram); ATF_TP_ADD_TC(tp, nvlist_send_recv__send_nvlist__stream); + ATF_TP_ADD_TC(tp, nvlist_send_recv__highfd); ATF_TP_ADD_TC(tp, nvlist_send_recv__send_closed_fd__dgram); ATF_TP_ADD_TC(tp, nvlist_send_recv__send_closed_fd__stream); ATF_TP_ADD_TC(tp, nvlist_send_recv__send_many_fds__dgram);home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?69f21a77.3a9f9.344b8d10>