The patch below does not apply to the 4.20-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From a55234dabe1f72cf22f9197980751d37e38ba020 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@xxxxxxxxxxxxxx>
Date: Fri, 11 Jan 2019 12:20:41 +0100
Subject: [PATCH] can: flexcan: fix NULL pointer exception during bringup
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Commit cbffaf7aa09e ("can: flexcan: Always use last mailbox for TX")
introduced a loop letting i run up to (including) ARRAY_SIZE(regs->mb)
and in the body accessed regs->mb[i] which is an out-of-bounds array
access that then resulted in an access to an reserved register area.
Later this was changed by commit 0517961ccdf1 ("can: flexcan: Add
provision for variable payload size") to iterate a bit differently but
still runs one iteration too much resulting to call
flexcan_get_mb(priv, priv->mb_count)
which results in a WARN_ON and then a NULL pointer exception. This
only affects devices compatible with "fsl,p1010-flexcan",
"fsl,imx53-flexcan", "fsl,imx35-flexcan", "fsl,imx25-flexcan",
"fsl,imx28-flexcan", so newer i.MX SoCs are not affected.
Fixes: cbffaf7aa09e ("can: flexcan: Always use last mailbox for TX")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Cc: linux-stable <stable@xxxxxxxxxxxxxxx> # >= 4.20
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 5f097648d12d..1c66fb2ad76b 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1106,7 +1106,7 @@ static int flexcan_chip_start(struct net_device *dev)
}
} else {
/* clear and invalidate unused mailboxes first */
- for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i <= priv->mb_count; i++) {
+ for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i < priv->mb_count; i++) {
mb = flexcan_get_mb(priv, i);
priv->write(FLEXCAN_MB_CODE_RX_INACTIVE,
&mb->can_ctrl);
