From 2fc6f337257f4f7c21ecff429241f7acaa6df4e8 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Tue, 31 Oct 2023 10:30:21 +0100 Subject: [PATCH] can: isotp: check CAN address family in isotp_bind() 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 Link: https://lore.kernel.org/all/20230104201844.13168-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- net/can/isotp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/can/isotp.c b/net/can/isotp.c index b5fdf30a69963..82e56f3dd2c65 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1129,6 +1129,9 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) 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) -- 2.47.3