2021-04-15 08:56:45

by Colin King

[permalink] [raw]
Subject: [PATCH][next] can: etas_es58x: Fix potential null pointer dereference on pointer cf

From: Colin Ian King <[email protected]>

The pointer cf is being null checked earlier in the code, however the
update of the rx_bytes statistics is dereferencing cf without null
checking cf. Fix this by moving the statement into the following code
block that has a null cf check.

Addresses-Coverity: ("Dereference after null check")
Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
Signed-off-by: Colin Ian King <[email protected]>
---
drivers/net/can/usb/etas_es58x/es58x_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
index 7222b3b6ca46..5198e1d6b6ad 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_core.c
+++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
@@ -856,9 +856,10 @@ int es58x_rx_err_msg(struct net_device *netdev, enum es58x_err error,
* consistency.
*/
netdev->stats.rx_packets++;
- netdev->stats.rx_bytes += cf->can_dlc;

if (cf) {
+ netdev->stats.rx_bytes += cf->can_dlc;
+
if (cf->data[1])
cf->can_id |= CAN_ERR_CRTL;
if (cf->data[2] || cf->data[3]) {
--
2.30.2


2021-04-15 09:05:17

by Marc Kleine-Budde

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Subject: Re: [PATCH][next] can: etas_es58x: Fix potential null pointer dereference on pointer cf

On 15.04.2021 09:55:35, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> The pointer cf is being null checked earlier in the code, however the
> update of the rx_bytes statistics is dereferencing cf without null
> checking cf. Fix this by moving the statement into the following code
> block that has a null cf check.
>
> Addresses-Coverity: ("Dereference after null check")
> Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
> Signed-off-by: Colin Ian King <[email protected]>

A somewhat different fix is already in net-next/master

https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=e2b1e4b532abdd39bfb7313146153815e370d60c

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

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2021-04-15 09:14:40

by Colin King

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Subject: Re: [PATCH][next] can: etas_es58x: Fix potential null pointer dereference on pointer cf

On 15/04/2021 10:03, Marc Kleine-Budde wrote:
> On 15.04.2021 09:55:35, Colin King wrote:
>> From: Colin Ian King <[email protected]>
>>
>> The pointer cf is being null checked earlier in the code, however the
>> update of the rx_bytes statistics is dereferencing cf without null
>> checking cf. Fix this by moving the statement into the following code
>> block that has a null cf check.
>>
>> Addresses-Coverity: ("Dereference after null check")
>> Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
>> Signed-off-by: Colin Ian King <[email protected]>
>
> A somewhat different fix is already in net-next/master
>
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=e2b1e4b532abdd39bfb7313146153815e370d60c

+1 on that

>
> Marc
>