This is a note to let you know that I've just added the patch titled
can: isotp: sanitize CAN ID checks in isotp_bind()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
can-isotp-sanitize-can-id-checks-in-isotp_bind.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bab2f29ab6673213bf5390111d25983914b86f3d
Author: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Date: Wed Mar 16 17:42:56 2022 +0100
can: isotp: sanitize CAN ID checks in isotp_bind()
[ Upstream commit 3ea566422cbde9610c2734980d1286ab681bb40e ]
Syzbot created an environment that lead to a state machine status that
can not be reached with a compliant CAN ID address configuration.
The provided address information consisted of CAN ID 0x6000001 and 0xC28001
which both boil down to 11 bit CAN IDs 0x001 in sending and receiving.
Sanitize the SFF/EFF CAN ID values before performing the address checks.
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/20220316164258.54155-1-socketcan@xxxxxxxxxxxx
Reported-by: syzbot+2339c27f5c66c652843e@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/can/isotp.c b/net/can/isotp.c
index d59f1758ac9c..9de6c3daed79 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1147,6 +1147,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
struct net *net = sock_net(sk);
int ifindex;
struct net_device *dev;
+ canid_t tx_id, rx_id;
int err = 0;
int notify_enetdown = 0;
int do_rx_reg = 1;
@@ -1154,8 +1155,18 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
if (len < ISOTP_MIN_NAMELEN)
return -EINVAL;
- if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
- return -EADDRNOTAVAIL;
+ /* sanitize tx/rx CAN identifiers */
+ tx_id = addr->can_addr.tp.tx_id;
+ if (tx_id & CAN_EFF_FLAG)
+ tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+ else
+ tx_id &= CAN_SFF_MASK;
+
+ rx_id = addr->can_addr.tp.rx_id;
+ if (rx_id & CAN_EFF_FLAG)
+ rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+ else
+ rx_id &= CAN_SFF_MASK;
if (!addr->can_ifindex)
return -ENODEV;
@@ -1167,21 +1178,13 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
do_rx_reg = 0;
/* do not validate rx address for functional addressing */
- if (do_rx_reg) {
- if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id) {
- err = -EADDRNOTAVAIL;
- goto out;
- }
-
- if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
- err = -EADDRNOTAVAIL;
- goto out;
- }
+ if (do_rx_reg && rx_id == tx_id) {
+ err = -EADDRNOTAVAIL;
+ goto out;
}
if (so->bound && addr->can_ifindex == so->ifindex &&
- addr->can_addr.tp.rx_id == so->rxid &&
- addr->can_addr.tp.tx_id == so->txid)
+ rx_id == so->rxid && tx_id == so->txid)
goto out;
dev = dev_get_by_index(net, addr->can_ifindex);
@@ -1205,16 +1208,14 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
ifindex = dev->ifindex;
if (do_rx_reg) {
- can_rx_register(net, dev, addr->can_addr.tp.rx_id,
- SINGLE_MASK(addr->can_addr.tp.rx_id),
+ can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
isotp_rcv, sk, "isotp", sk);
/* no consecutive frame echo skb in flight */
so->cfecho = 0;
/* register for echo skb's */
- can_rx_register(net, dev, addr->can_addr.tp.tx_id,
- SINGLE_MASK(addr->can_addr.tp.tx_id),
+ can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
isotp_rcv_echo, sk, "isotpe", sk);
}
@@ -1238,8 +1239,8 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
/* switch to new settings */
so->ifindex = ifindex;
- so->rxid = addr->can_addr.tp.rx_id;
- so->txid = addr->can_addr.tp.tx_id;
+ so->rxid = rx_id;
+ so->txid = tx_id;
so->bound = 1;
out:
