On Mon, Mar 11, 2024 at 02:52:19PM +0800, Xu Yang wrote:
> When unregister pd capabilitie in tcpm, KASAN will capture below double
> -free issue. The root cause is the same capabilitiy will be kfreed twice,
> the first time is kfreed by pd_capabilities_release() and the second time
> is explicitly kfreed by tcpm_port_unregister_pd().
>
> [ 3.988059] BUG: KASAN: double-free in tcpm_port_unregister_pd+0x1a4/0x3dc
> [ 3.995001] Free of addr ffff0008164d3000 by task kworker/u16:0/10
> [ 4.001206]
> [ 4.002712] CPU: 2 PID: 10 Comm: kworker/u16:0 Not tainted 6.8.0-rc5-next-20240220-05616-g52728c567a55 #53
> [ 4.012402] Hardware name: Freescale i.MX8QXP MEK (DT)
> [ 4.017569] Workqueue: events_unbound deferred_probe_work_func
> [ 4.023456] Call trace:
> [ 4.025920] dump_backtrace+0x94/0xec
> [ 4.029629] show_stack+0x18/0x24
> [ 4.032974] dump_stack_lvl+0x78/0x90
> [ 4.036675] print_report+0xfc/0x5c0
> [ 4.040289] kasan_report_invalid_free+0xa0/0xc0
> [ 4.044937] __kasan_slab_free+0x124/0x154
> [ 4.049072] kfree+0xb4/0x1e8
> [ 4.052069] tcpm_port_unregister_pd+0x1a4/0x3dc
> [ 4.056725] tcpm_register_port+0x1dd0/0x2558
> [ 4.061121] tcpci_register_port+0x420/0x71c
> [ 4.065430] tcpci_probe+0x118/0x2e0
>
> To fix the issue, this will remove kree() from tcpm_port_unregister_pd().
>
> Fixes: cd099cde4ed2 ("usb: typec: tcpm: Support multiple capabilities")
> cc: <stable@xxxxxxxxxxxxxxx>
> Suggested-by: Aisheng Dong <aisheng.dong@xxxxxxx>
> Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 3d505614bff1..afbb0d832db2 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -6940,9 +6940,7 @@ static void tcpm_port_unregister_pd(struct tcpm_port *port)
> port->port_source_caps = NULL;
> for (i = 0; i < port->pd_count; i++) {
> usb_power_delivery_unregister_capabilities(port->pd_list[i]->sink_cap);
> - kfree(port->pd_list[i]->sink_cap);
> usb_power_delivery_unregister_capabilities(port->pd_list[i]->source_cap);
> - kfree(port->pd_list[i]->source_cap);
> devm_kfree(port->dev, port->pd_list[i]);
> port->pd_list[i] = NULL;
> usb_power_delivery_unregister(port->pds[i]);
> --
> 2.34.1
--
heikki
