can: can_dropped_invalid_skb(): ensure an initialized headroom in outgoing CAN sk_buffs
KMSAN sysbot detected a read access to an untinitialized value in the headroom of an outgoing CAN related sk_buff. When using CAN sockets this area is filled appropriately - but when using a packet socket this initialization is missing. The problematic read access occurs in the CAN receive path which can only be triggered when the sk_buff is sent through a (virtual) CAN interface. So we check in the sending path whether we need to perform the missing initializations. Fixes: d3b58c47 ("can: replace timestamp as unique skb attribute") Reported-by:<syzbot+b02ff0707a97e4e79ebb@syzkaller.appspotmail.com> Signed-off-by:
Oliver Hartkopp <socketcan@hartkopp.net> Tested-by:
Oliver Hartkopp <socketcan@hartkopp.net> Cc: linux-stable <stable@vger.kernel.org> # >= v4.1 Signed-off-by:
Marc Kleine-Budde <mkl@pengutronix.de>
parent
93bdc0eb
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