Commit 430d67bd authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Jakub Kicinski
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net: hsr: Use the seqnr lock for frames received via interlink port. 



syzbot reported that the seqnr_lock is not acquire for frames received
over the interlink port. In the interlink case a new seqnr is generated
and assigned to the frame.
Frames, which are received over the slave port have already a sequence
number assigned so the lock is not required.

Acquire the hsr_priv::seqnr_lock during in the invocation of
hsr_forward_skb() if a packet has been received from the interlink port.

Reported-by: default avatar <syzbot+3d602af7549af539274e@syzkaller.appspotmail.com>
Closes: https://groups.google.com/g/syzkaller-bugs/c/KppVvGviGg4/m/EItSdCZdBAAJ


Fixes: 5055cccf ("net: hsr: Provide RedBox support (HSR-SAN)")
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: default avatarLukasz Majewski <lukma@denx.de>
Tested-by: default avatarLukasz Majewski <lukma@denx.de>
Link: https://patch.msgid.link/20240906132816.657485-2-bigeasy@linutronix.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a18c097e

net/hsr/hsr_slave.c

+10 −1
Original line number Diff line number Diff line
@@ -67,7 +67,16 @@ static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb) 
		skb_set_network_header(skb, ETH_HLEN + HSR_HLEN);

	skb_reset_mac_len(skb);



	/* Only the frames received over the interlink port will assign a

	 * sequence number and require synchronisation vs other sender.

	 */

	if (port->type == HSR_PT_INTERLINK) {

		spin_lock_bh(&hsr->seqnr_lock);

		hsr_forward_skb(skb, port);

		spin_unlock_bh(&hsr->seqnr_lock);

	} else {

		hsr_forward_skb(skb, port);

	}



finish_consume:

	return RX_HANDLER_CONSUMED;