From: Roy Marples <roy@marples.name>
Date: Mon, 28 Sep 2020 20:10:21 +0000 (+0100)
Subject: privsep: fix crash when interface departs before bpf returns for it
X-Git-Tag: v9.3.0~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c35a09f0dffba170cb46323b66fce92e2b47256f;p=thirdparty%2Fdhcpcd.git

privsep: fix crash when interface departs before bpf returns for it
---

diff --git a/src/dhcp.c b/src/dhcp.c
index 61cc256a..923c5af5 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -3477,6 +3477,9 @@ dhcp_packet(struct interface *ifp, uint8_t *data, size_t len,
 #ifdef PRIVSEP
 	const struct dhcp_state *state = D_CSTATE(ifp);
 
+	if (state == NULL)
+		return;
+
 	/* Ignore double reads */
 	if (IN_PRIVSEP(ifp->ctx)) {
 		switch (state->state) {
diff --git a/src/privsep-bpf.c b/src/privsep-bpf.c
index f7662333..f8240f12 100644
--- a/src/privsep-bpf.c
+++ b/src/privsep-bpf.c
@@ -266,6 +266,10 @@ ps_bpf_dispatch(struct dhcpcd_ctx *ctx,
 	size_t bpf_len;
 
 	ifp = if_findindex(ctx->ifaces, psm->ps_id.psi_ifindex);
+	/* interface may have departed .... */
+	if (ifp == NULL)
+		return -1;
+
 	bpf = iov->iov_base;
 	bpf_len = iov->iov_len;