Add missing check to block non-AF_CAN binds.
Syzbot created some code which matched the right sockaddr struct size
but used AF_XDP (0x2C) instead of AF_CAN (0x1D) in the address family
field:
bind$xdp(r2, &(0x7f0000000540)={0x2c, 0x0, r4, 0x0, r2}, 0x10)
^^^^
This has no funtional impact but the userspace should be notified about
the wrong address family field content.
Link: https://syzkaller.appspot.com/text?tag=CrashLog&x=11ff9d8c480000
Reported-by: syzbot+5aed6c3aaba661f5b917@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
net/can/isotp.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/can/isotp.c b/net/can/isotp.c
index fc81d77724a1..9bc344851704 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1218,10 +1218,13 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
int notify_enetdown = 0;
if (len < ISOTP_MIN_NAMELEN)
return -EINVAL;
+ if (addr->can_family != AF_CAN)
+ return -EINVAL;
+
/* sanitize tx CAN identifier */
if (tx_id & CAN_EFF_FLAG)
tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
else
tx_id &= CAN_SFF_MASK;
--
2.35.1
