From: Roy Marples <roy@marples.name>
Date: Mon, 25 Sep 2023 09:34:12 +0000 (+0100)
Subject: Guard against handling many SIGTERM/SIGINT.
X-Git-Tag: v10.0.3~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dcaf729bcaa7d9059fecb8231f395c5a0be293e0;p=thirdparty%2Fdhcpcd.git

Guard against handling many SIGTERM/SIGINT.

Privsep has a mini-eloop for reading data from other processes.
This mini-eloop processes signals as well so we can reap children.
During teardown we don't want to process SIGTERM or SIGINT again,
as that could trigger memory issues.

Hopefully fixes #247.
---

diff --git a/src/dhcpcd.c b/src/dhcpcd.c
index 0cc62226..5de55faf 100644
--- a/src/dhcpcd.c
+++ b/src/dhcpcd.c
@@ -1414,6 +1414,7 @@ dhcpcd_renew(struct dhcpcd_ctx *ctx)
 
 #ifdef USE_SIGNALS
 #define sigmsg "received %s, %s"
+static volatile bool dhcpcd_exiting = false;
 void
 dhcpcd_signal_cb(int sig, void *arg)
 {
@@ -1486,9 +1487,20 @@ dhcpcd_signal_cb(int sig, void *arg)
 		return;
 	}
 
+	/*
+	 * Privsep has a mini-eloop for reading data from other processes.
+	 * This mini-eloop processes signals as well so we can reap children.
+	 * During teardown we don't want to process SIGTERM or SIGINT again,
+	 * as that could trigger memory issues.
+	 */
+	if (dhcpcd_exiting)
+		return;
+
+	dhcpcd_exiting = true;
 	if (!(ctx->options & DHCPCD_TEST))
 		stop_all_interfaces(ctx, opts);
 	eloop_exit(ctx->eloop, exit_code);
+	dhcpcd_exiting = false;
 }
 #endif