From 4fb6e9eddc7487a965b3e051115f9bb1d0413342 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 4 Nov 2022 18:20:47 +0100 Subject: [PATCH] process-util: add new FORK_CLOEXEC_OFF flag for disabling O_CLOEXEC on remaining fds Often the fds that shall stay around in the child shall be passed to a process over execve(), hence add an option to explicitly disable O_CLOEXEC on them in the child. (cherry picked from commit 981cfbe046297a18f2cb115ef81202f3bd68d2a3) Related: #2138081 --- src/basic/process-util.c | 8 ++++++++ src/basic/process-util.h | 1 + 2 files changed, 9 insertions(+) diff --git a/src/basic/process-util.c b/src/basic/process-util.c index fb0b38fa49..0213f5913f 100644 --- a/src/basic/process-util.c +++ b/src/basic/process-util.c @@ -1372,6 +1372,14 @@ int safe_fork_full( } } + if (flags & FORK_CLOEXEC_OFF) { + r = fd_cloexec_many(except_fds, n_except_fds, false); + if (r < 0) { + log_full_errno(prio, r, "Failed to turn off O_CLOEXEC on file descriptors: %m"); + _exit(EXIT_FAILURE); + } + } + /* When we were asked to reopen the logs, do so again now */ if (flags & FORK_REOPEN_LOG) { log_open(); diff --git a/src/basic/process-util.h b/src/basic/process-util.h index f8c374a310..ed2f73673e 100644 --- a/src/basic/process-util.h +++ b/src/basic/process-util.h @@ -150,6 +150,7 @@ typedef enum ForkFlags { FORK_STDOUT_TO_STDERR = 1 << 11, /* Make stdout a copy of stderr */ FORK_FLUSH_STDIO = 1 << 12, /* fflush() stdout (and stderr) before forking */ FORK_NEW_USERNS = 1 << 13, /* Run child in its own user namespace */ + FORK_CLOEXEC_OFF = 1 << 14, /* In the child: turn off O_CLOEXEC on all fds in except_fds[] */ } ForkFlags; int safe_fork_full(const char *name, const int except_fds[], size_t n_except_fds, ForkFlags flags, pid_t *ret_pid);