commit c6adf659a8ba85913e16a571d5a9bcd17d3d1234 upstream
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@syzkaller.appspotmail.com Signed-off-by: Oliver Hartkopp socketcan@hartkopp.net Link: https://lore.kernel.org/all/20230104201844.13168-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- net/can/isotp.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/can/isotp.c b/net/can/isotp.c index b5fdf30a6996..82e56f3dd2c6 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1127,10 +1127,13 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) int do_rx_reg = 1;
if (len < ISOTP_MIN_NAMELEN) return -EINVAL;
+ if (addr->can_family != AF_CAN) + return -EINVAL; + /* 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