Block SIGCHLD when executing mount and umount

1 files changed, 36 insertions, 12 deletions

diff --git a/lib/mount_util.c b/lib/mount_util.c
index 39a1e6f..fc56255 100644
--- a/lib/mount_util.c
+++ b/lib/mount_util.c
@@ -39,19 +39,30 @@ int fuse_mnt_add_mount(const char *progname, const char *fsname,
 {
 	int res;
 	int status;
+	sigset_t blockmask;
+	sigset_t oldmask;
 
 	if (!mtab_needs_update(mnt))
 		return 0;
 
+	sigemptyset(&blockmask);
+	sigaddset(&blockmask, SIGCHLD);
+	res = sigprocmask(SIG_BLOCK, &blockmask, &oldmask);
+	if (res == -1) {
+		fprintf(stderr, "%s: sigprocmask: %s\n", progname, strerror(errno));
+		return -1;
+	}
+
 	res = fork();
 	if (res == -1) {
 		fprintf(stderr, "%s: fork: %s\n", progname, strerror(errno));
-		return -1;
+		goto out_restore;
 	}
 	if (res == 0) {
 		char templ[] = "/tmp/fusermountXXXXXX";
 		char *tmp;
 
+		sigprocmask(SIG_SETMASK, &oldmask, NULL);
 		setuid(geteuid());
 
 		/*
@@ -78,20 +89,23 @@ int fuse_mnt_add_mount(const char *progname, const char *fsname,
 		exit(1);
 	}
 	res = waitpid(res, &status, 0);
-	if (res == -1) {
+	if (res == -1)
 		fprintf(stderr, "%s: waitpid: %s\n", progname, strerror(errno));
-		return -1;
-	}
+
 	if (status != 0)
-		return -1;
+		res = -1;
 
-	return 0;
+ out_restore:
+	sigprocmask(SIG_SETMASK, &oldmask, NULL);
+	return res;
 }
 
 int fuse_mnt_umount(const char *progname, const char *mnt, int lazy)
 {
 	int res;
 	int status;
+	sigset_t blockmask;
+	sigset_t oldmask;
 
 	if (!mtab_needs_update(mnt)) {
 		res = umount2(mnt, lazy ? 2 : 0);
@@ -101,12 +115,21 @@ int fuse_mnt_umount(const char *progname, const char *mnt, int lazy)
 		return res;
 	}
 
+	sigemptyset(&blockmask);
+	sigaddset(&blockmask, SIGCHLD);
+	res = sigprocmask(SIG_BLOCK, &blockmask, &oldmask);
+	if (res == -1) {
+		fprintf(stderr, "%s: sigprocmask: %s\n", progname, strerror(errno));
+		return -1;
+	}
+
 	res = fork();
 	if (res == -1) {
 		fprintf(stderr, "%s: fork: %s\n", progname, strerror(errno));
-		return -1;
+		goto out_restore;
 	}
 	if (res == 0) {
+		sigprocmask(SIG_SETMASK, &oldmask, NULL);
 		setuid(geteuid());
 		execl("/bin/umount", "/bin/umount", "-i", mnt,
 		      lazy ? "-l" : NULL, NULL);
@@ -115,14 +138,15 @@ int fuse_mnt_umount(const char *progname, const char *mnt, int lazy)
 		exit(1);
 	}
 	res = waitpid(res, &status, 0);
-	if (res == -1) {
+	if (res == -1)
 		fprintf(stderr, "%s: waitpid: %s\n", progname, strerror(errno));
-		return -1;
-	}
+
 	if (status != 0)
-		return -1;
+		res = -1;
 
-	return 0;
+ out_restore:
+	sigprocmask(SIG_SETMASK, &oldmask, NULL);
+	return res;
 }
 
 char *fuse_mnt_resolve_path(const char *progname, const char *orig)