usb: typec: tcpm: fix double-free issue in tcpm_port_unregister_pd()

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@vger.kernel.org
Suggested-by: Aisheng Dong <aisheng.dong@nxp.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240311065219.777037-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index d63a36b1354956b85d1fd54559212404b940e764..64cbcab6f46ad5f12a546e1893fdeb680b07b7de 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -6943,9 +6943,7 @@ 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]);