open files O_CLOEXEC|O_EXCL

Dumb patch that adds O_CLOEXEC to all open/fopen
calls, even where it is obviously pointless.

While at it, also add O_EXCL where it might be
considered useful, for example to clear Coverity
warnings, or on files that subsequently are used
to configure a join sandbox.

Pure defense in depth, this patch should have no
observable effects.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/firejail/fs_dev.c b/src/firejail/fs_dev.c
index 2f0067c93..8c2870a4d 100644
--- a/src/firejail/fs_dev.c
+++ b/src/firejail/fs_dev.c
@@ -122,7 +122,7 @@ static void deventry_mount(void) {
                                                 i++;
                                                 continue;
                                         }
-                                        FILE *fp = fopen(dev[i].dev_fname, "w");
+                                        FILE *fp = fopen(dev[i].dev_fname, "we");
                                         if (fp) {
                                                 fprintf(fp, "\n");
                                                 SET_PERMS_STREAM(fp, s.st_uid, s.st_gid, s.st_mode);
@@ -218,7 +218,7 @@ void fs_private_dev(void){
         struct stat s;
         if (stat("/dev/log", &s) == 0) {
                 have_devlog = 1;
-                FILE *fp = fopen(RUN_DEVLOG_FILE, "w");
+                FILE *fp = fopen(RUN_DEVLOG_FILE, "we");
                 if (!fp)
                         have_devlog = 0;
                 else {
@@ -239,7 +239,7 @@ void fs_private_dev(void){
 
         // bring back /dev/log
         if (have_devlog) {
-                FILE *fp = fopen("/dev/log", "w");
+                FILE *fp = fopen("/dev/log", "we");
                 if (fp) {
                         fprintf(fp, "\n");
                         fclose(fp);