can: j1939: j1939_xtp_rx_rts_session_new(): abort TP less than 9 bytes
authorZhang Changzhong <zhangchangzhong@huawei.com>
Thu, 14 Oct 2021 09:26:40 +0000 (17:26 +0800)
committerMarc Kleine-Budde <mkl@pengutronix.de>
Sun, 17 Oct 2021 12:12:57 +0000 (14:12 +0200)
commita4fbe70c5cb746441d56b28cf88161d9e0e25378
tree22b2215bcd7d3637dea36cca04d5bd2681793b34
parent379743985ab6cfe2cbd32067cf4ed497baca6d06
can: j1939: j1939_xtp_rx_rts_session_new(): abort TP less than 9 bytes

The receiver should abort TP if 'total message size' in TP.CM_RTS and
TP.CM_BAM is less than 9 or greater than 1785 [1], but currently the
j1939 stack only checks the upper bound and the receiver will accept
the following broadcast message:

  vcan1  18ECFF00   [8]  20 08 00 02 FF 00 23 01
  vcan1  18EBFF00   [8]  01 00 00 00 00 00 00 00
  vcan1  18EBFF00   [8]  02 00 FF FF FF FF FF FF

This patch adds check for the lower bound and abort illegal TP.

[1] SAE-J1939-82 A.3.4 Row 2 and A.3.6 Row 6.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/all/1634203601-3460-1-git-send-email-zhangchangzhong@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
net/can/j1939/j1939-priv.h
net/can/j1939/transport.c