diff mbox series

[v2,04/12] can: hi311x: fix txerr and rxerr reporting

Message ID 20241122221650.633981-5-dario.binacchi@amarulasolutions.com
State New
Headers
Series Fix {rx,tx}_errors CAN statistics |

Commit Message

Dario Binacchi Nov. 22, 2024, 10:15 p.m. UTC 
The commit a22bd630cfff ("can: hi311x: do not report txerr and rxerr
during bus-off") removed the reporting of rxerr and txerr even in case
of correct operation (i. e. not bus-off). The CAN frame is unnecessarily
set since netif_rx() has already been called. The patch fixes the issue
by postponing the netif_rx() call in case of txerr and rxerr reporting.

Fixes: a22bd630cfff ("can: hi311x: do not report txerr and rxerr during bus-off")
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

Changes in v2:
- Added in v2

 drivers/net/can/spi/hi311x.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Marc Kleine-Budde Nov. 26, 2024, 9:48 a.m. UTC | #1 
On 22.11.2024 23:15:45, Dario Binacchi wrote:
> The commit a22bd630cfff ("can: hi311x: do not report txerr and rxerr
> during bus-off") removed the reporting of rxerr and txerr even in case
> of correct operation (i. e. not bus-off). The CAN frame is unnecessarily
> set since netif_rx() has already been called. The patch fixes the issue
> by postponing the netif_rx() call in case of txerr and rxerr reporting.

re-phrased to:

can: hi311x: hi3110_can_ist(): fix potential use-after-free

The commit a22bd630cfff ("can: hi311x: do not report txerr and rxerr
during bus-off") removed the reporting of rxerr and txerr even in case
of correct operation (i. e. not bus-off).

The error count information added to the CAN frame after netif_rx() is
a potential use after free, since there is no guarantee that the skb
is in the same state. It might be freed or reused.

Fix the issue by postponing the netif_rx() call in case of txerr and
rxerr reporting.

> Fixes: a22bd630cfff ("can: hi311x: do not report txerr and rxerr during bus-off")
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

regards,
Marc
diff mbox series

Patch

diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
index 148d974ebb21..b67464df25ff 100644
--- a/drivers/net/can/spi/hi311x.c
+++ b/drivers/net/can/spi/hi311x.c
@@ -671,9 +671,9 @@  static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
 			tx_state = txerr >= rxerr ? new_state : 0;
 			rx_state = txerr <= rxerr ? new_state : 0;
 			can_change_state(net, cf, tx_state, rx_state);
-			netif_rx(skb);
 
 			if (new_state == CAN_STATE_BUS_OFF) {
+				netif_rx(skb);
 				can_bus_off(net);
 				if (priv->can.restart_ms == 0) {
 					priv->force_quit = 1;
@@ -684,6 +684,7 @@  static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
 				cf->can_id |= CAN_ERR_CNT;
 				cf->data[6] = txerr;
 				cf->data[7] = rxerr;
+				netif_rx(skb);
 			}
 		}