From: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx> [ Upstream commit 9ad86d377ef4a19c75a9c639964879a5b25a433b ] 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@xxxxxxxxxxxxxxxxxxxx> Link: https://patch.msgid.link/20241122221650.633981-5-dario.binacchi@xxxxxxxxxxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> [kovalev: changed the call order of netif_rx_ni() according to netif_rx() of the upstream patch] Signed-off-by: Vasiliy Kovalev <kovalev@xxxxxxxxxxxx> --- Backport to fix CVE-2024-56651 Link: https://www.cve.org/CVERecord/?id=CVE-2024-56651 --- drivers/net/can/spi/hi311x.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c index 28273e84171a25..1cdc05475cda61 100644 --- a/drivers/net/can/spi/hi311x.c +++ b/drivers/net/can/spi/hi311x.c @@ -673,9 +673,9 @@ 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_ni(skb); if (new_state == CAN_STATE_BUS_OFF) { + netif_rx_ni(skb); can_bus_off(net); if (priv->can.restart_ms == 0) { priv->force_quit = 1; @@ -685,6 +685,7 @@ static irqreturn_t hi3110_can_ist(int irq, void *dev_id) } else { cf->data[6] = txerr; cf->data[7] = rxerr; + netif_rx_ni(skb); } } -- 2.33.8