From 55cf5a255a4b65bc898e5287fa9d939768997dff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=BD=D0=B0=D0=B1?= <nabijaczleweli@nabijaczleweli.xyz>
Date: Mon, 12 Apr 2021 14:07:14 +0200
Subject: [PATCH] zed: set O_CLOEXEC on persistent fds, remove closefrom() from
 pre-exec
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Also don't dup /dev/null over stdio if daemonised

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11891
---
 cmd/zed/zed_conf.c  | 11 ++++-------
 cmd/zed/zed_event.c |  2 +-
 cmd/zed/zed_exec.c  |  9 ++++-----
 3 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/cmd/zed/zed_conf.c b/cmd/zed/zed_conf.c
index b66b67b530..b95108fd2f 100644
--- a/cmd/zed/zed_conf.c
+++ b/cmd/zed/zed_conf.c
@@ -425,8 +425,6 @@ zed_conf_scan_dir(struct zed_conf *zcp)
 int
 zed_conf_write_pid(struct zed_conf *zcp)
 {
-	const mode_t dirmode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
-	const mode_t filemode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
 	char buf[PATH_MAX];
 	int n;
 	char *p;
@@ -454,7 +452,7 @@ zed_conf_write_pid(struct zed_conf *zcp)
 	if (p)
 		*p = '\0';
 
-	if ((mkdirp(buf, dirmode) < 0) && (errno != EEXIST)) {
+	if ((mkdirp(buf, 0755) < 0) && (errno != EEXIST)) {
 		zed_log_msg(LOG_ERR, "Failed to create directory \"%s\": %s",
 		    buf, strerror(errno));
 		goto err;
@@ -464,7 +462,7 @@ zed_conf_write_pid(struct zed_conf *zcp)
 	 */
 	mask = umask(0);
 	umask(mask | 022);
-	zcp->pid_fd = open(zcp->pid_file, (O_RDWR | O_CREAT), filemode);
+	zcp->pid_fd = open(zcp->pid_file, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
 	umask(mask);
 	if (zcp->pid_fd < 0) {
 		zed_log_msg(LOG_ERR, "Failed to open PID file \"%s\": %s",
@@ -529,7 +527,6 @@ int
 zed_conf_open_state(struct zed_conf *zcp)
 {
 	char dirbuf[PATH_MAX];
-	mode_t dirmode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
 	int n;
 	char *p;
 	int rv;
@@ -551,7 +548,7 @@ zed_conf_open_state(struct zed_conf *zcp)
 	if (p)
 		*p = '\0';
 
-	if ((mkdirp(dirbuf, dirmode) < 0) && (errno != EEXIST)) {
+	if ((mkdirp(dirbuf, 0755) < 0) && (errno != EEXIST)) {
 		zed_log_msg(LOG_WARNING,
 		    "Failed to create directory \"%s\": %s",
 		    dirbuf, strerror(errno));
@@ -569,7 +566,7 @@ zed_conf_open_state(struct zed_conf *zcp)
 		(void) unlink(zcp->state_file);
 
 	zcp->state_fd = open(zcp->state_file,
-	    (O_RDWR | O_CREAT), (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH));
+	    O_RDWR | O_CREAT | O_CLOEXEC, 0644);
 	if (zcp->state_fd < 0) {
 		zed_log_msg(LOG_WARNING, "Failed to open state file \"%s\": %s",
 		    zcp->state_file, strerror(errno));
diff --git a/cmd/zed/zed_event.c b/cmd/zed/zed_event.c
index 5e28bb22ce..232b88a138 100644
--- a/cmd/zed/zed_event.c
+++ b/cmd/zed/zed_event.c
@@ -54,7 +54,7 @@ zed_event_init(struct zed_conf *zcp)
 		zed_log_die("Failed to initialize libzfs");
 	}
 
-	zcp->zevent_fd = open(ZFS_DEV, O_RDWR);
+	zcp->zevent_fd = open(ZFS_DEV, O_RDWR | O_CLOEXEC);
 	if (zcp->zevent_fd < 0) {
 		if (zcp->do_idle)
 			return (-1);
diff --git a/cmd/zed/zed_exec.c b/cmd/zed/zed_exec.c
index b1756c5386..8c8452ca7a 100644
--- a/cmd/zed/zed_exec.c
+++ b/cmd/zed/zed_exec.c
@@ -27,7 +27,6 @@
 #include <unistd.h>
 #include <pthread.h>
 #include "zed_exec.h"
-#include "zed_file.h"
 #include "zed_log.h"
 #include "zed_strings.h"
 
@@ -116,7 +115,7 @@ _zed_exec_create_env(zed_strings_t *zsp)
  */
 static void
 _zed_exec_fork_child(uint64_t eid, const char *dir, const char *prog,
-    char *env[], int zfd)
+    char *env[], int zfd, boolean_t in_foreground)
 {
 	char path[PATH_MAX];
 	int n;
@@ -154,13 +153,13 @@ _zed_exec_fork_child(uint64_t eid, const char *dir, const char *prog,
 		(void) sigprocmask(SIG_SETMASK, &mask, NULL);
 
 		(void) umask(022);
-		if ((fd = open("/dev/null", O_RDWR)) != -1) {
+		if (in_foreground && /* we're already devnulled if daemonised */
+		    (fd = open("/dev/null", O_RDWR | O_CLOEXEC)) != -1) {
 			(void) dup2(fd, STDIN_FILENO);
 			(void) dup2(fd, STDOUT_FILENO);
 			(void) dup2(fd, STDERR_FILENO);
 		}
 		(void) dup2(zfd, ZEVENT_FILENO);
-		zed_file_close_from(ZEVENT_FILENO + 1);
 		execle(path, prog, NULL, env);
 		_exit(127);
 	}
@@ -359,7 +358,7 @@ zed_exec_process(uint64_t eid, const char *class, const char *subclass,
 			n = strlen(*csp);
 			if ((strncmp(z, *csp, n) == 0) && !isalpha(z[n]))
 				_zed_exec_fork_child(eid, zcp->zedlet_dir,
-				    z, e, zcp->zevent_fd);
+				    z, e, zcp->zevent_fd, zcp->do_foreground);
 		}
 	}
 	free(e);