[PATCH 2/3] can: isotp: fix msg_namelen values depending on CAN_REQUIRED_SIZE
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: 2021-03-25 13:00:03
Subsystem:
can network layer, the rest · Maintainers:
Oliver Hartkopp, Marc Kleine-Budde, Linus Torvalds
Since commit f5223e9eee65 ("can: extend sockaddr_can to include j1939
members") the sockaddr_can has been extended in size and a new
CAN_REQUIRED_SIZE macro has been introduced to calculate the protocol
specific needed size.
The ABI for the msg_name and msg_namelen has not been adapted to the
new CAN_REQUIRED_SIZE macro for the other CAN protocols which leads
to a problem when an existing binary reads the (increased)
struct sockaddr_can in msg_name.
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t (local)
Reported-by: Richard Weinberger <richard@nod.at>
Acked-by: Kurt Van Dijck <redacted>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
net/can/isotp.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/net/can/isotp.c b/net/can/isotp.c
index 15ea1234d457..9f94ad3caee9 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c@@ -75,10 +75,12 @@ MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol"); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>"); MODULE_ALIAS("can-proto-6"); +#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp) + #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \ (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
@@ -984,11 +986,12 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, } sock_recv_timestamp(msg, sk, skb); if (msg->msg_name) { - msg->msg_namelen = sizeof(struct sockaddr_can); + __sockaddr_check_size(ISOTP_MIN_NAMELEN); + msg->msg_namelen = ISOTP_MIN_NAMELEN; memcpy(msg->msg_name, skb->cb, msg->msg_namelen); } skb_free_datagram(sk, skb);
@@ -1054,11 +1057,11 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) struct net_device *dev; int err = 0; int notify_enetdown = 0; int do_rx_reg = 1; - if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)) + if (len < ISOTP_MIN_NAMELEN) return -EINVAL; /* do not register frame reception for functional addressing */ if (so->opt.flags & CAN_ISOTP_SF_BROADCAST) do_rx_reg = 0;
@@ -1150,17 +1153,17 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer) struct isotp_sock *so = isotp_sk(sk); if (peer) return -EOPNOTSUPP; - memset(addr, 0, sizeof(*addr)); + memset(addr, 0, ISOTP_MIN_NAMELEN); addr->can_family = AF_CAN; addr->can_ifindex = so->ifindex; addr->can_addr.tp.rx_id = so->rxid; addr->can_addr.tp.tx_id = so->txid; - return sizeof(*addr); + return ISOTP_MIN_NAMELEN; } static int isotp_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, unsigned int optlen) {
--
2.30.2