webserver: reopen stdin from /dev/null.

Having both lacme(8) and its webserver component reading from the same
standard input could yield starvation.

2 files changed, 2 insertions, 0 deletions

diff --git a/Changelog b/Changelog
index 35503e9..c476ee1 100644
--- a/Changelog
+++ b/Changelog
@@ -51,6 +51,7 @@ lacme (0.7.1) upstream;
    $(sbindir)/lacme.
  - client: avoid "Use of uninitialized value in pattern match (m//)"
    perl warnings when the accountd socket can't be reached.
+ - webserver: reopen stdin from /dev/null.
 
  -- Guilhem Moulin <guilhem@fripost.org>  Wed, 09 Dec 2020 18:23:22 +0100
 
diff --git a/lacme b/lacme
index a5ba9f4..e5f8715 100755
--- a/lacme
+++ b/lacme
@@ -374,6 +374,7 @@ sub spawn_webserver() {
         my $pid = fork() // "fork: $!";
         unless ($pid) {
             drop_privileges($conf->{user}, $conf->{group}, $tmpdir);
+            open STDIN, '<', '/dev/null' or die "open(/dev/null): $!";
             set_FD_CLOEXEC($sock, 0);
             $ENV{DEBUG} = $OPTS{debug};
             # use execve(2) rather than a Perl pseudo-process to ensure that