git: 56bfa62faab4 - stable/12 - dhclient(8): Verify lease-, renewal- and rebinding-time option sizes.
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Date: Mon, 21 Nov 2022 20:41:49 UTC
The branch stable/12 has been updated by hselasky:
URL: https://cgit.FreeBSD.org/src/commit/?id=56bfa62faab489e6b1f1c1fa849a0eea2667825e
commit 56bfa62faab489e6b1f1c1fa849a0eea2667825e
Author: Hans Petter Selasky <hselasky@FreeBSD.org>
AuthorDate: 2022-11-14 14:20:09 +0000
Commit: Hans Petter Selasky <hselasky@FreeBSD.org>
CommitDate: 2022-11-21 20:41:07 +0000
dhclient(8): Verify lease-, renewal- and rebinding-time option sizes.
Else out-of-bound reads and undefined behaviour may happen.
The current code only checked for the presence of the first of four bytes.
Make sure the fields in question have the minium size required.
No functional change intended.
Reviewed by: rrs@
Sponsored by: NVIDIA Networking
(cherry picked from commit 3492caf512ae090816b4ffa275be43b2f5cfc460)
---
sbin/dhclient/dhclient.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index 628490874e69..f266a4aa3761 100644
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -798,7 +798,7 @@ dhcpack(struct packet *packet)
ACTION_SUPERSEDE)
ip->client->new->expiry = getULong(
ip->client->config->defaults[DHO_DHCP_LEASE_TIME].data);
- else if (ip->client->new->options[DHO_DHCP_LEASE_TIME].data)
+ else if (ip->client->new->options[DHO_DHCP_LEASE_TIME].len >= 4)
ip->client->new->expiry = getULong(
ip->client->new->options[DHO_DHCP_LEASE_TIME].data);
else
@@ -821,7 +821,7 @@ dhcpack(struct packet *packet)
ACTION_SUPERSEDE)
ip->client->new->renewal = getULong(
ip->client->config->defaults[DHO_DHCP_RENEWAL_TIME].data);
- else if (ip->client->new->options[DHO_DHCP_RENEWAL_TIME].len)
+ else if (ip->client->new->options[DHO_DHCP_RENEWAL_TIME].len >= 4)
ip->client->new->renewal = getULong(
ip->client->new->options[DHO_DHCP_RENEWAL_TIME].data);
else
@@ -835,7 +835,7 @@ dhcpack(struct packet *packet)
ACTION_SUPERSEDE)
ip->client->new->rebind = getULong(
ip->client->config->defaults[DHO_DHCP_REBINDING_TIME].data);
- else if (ip->client->new->options[DHO_DHCP_REBINDING_TIME].len)
+ else if (ip->client->new->options[DHO_DHCP_REBINDING_TIME].len >= 4)
ip->client->new->rebind = getULong(
ip->client->new->options[DHO_DHCP_REBINDING_TIME].data);
else