typec_register_partner() does not guarantee partner registration to always succeed. In the event of failure, port->partner is set to the error value or NULL. Given that port->partner validity is not checked, this results in the following crash:
Unable to handle kernel NULL pointer dereference at virtual address xx pc : run_state_machine+0x1bc8/0x1c08 lr : run_state_machine+0x1b90/0x1c08 .. Call trace: run_state_machine+0x1bc8/0x1c08 tcpm_state_machine_work+0x94/0xe4 kthread_worker_fn+0x118/0x328 kthread+0x1d0/0x23c ret_from_fork+0x10/0x20
To prevent the crash, check for port->partner validity before derefencing it in all the call sites.
Cc: stable@vger.kernel.org Fixes: c97cd0b4b54e ("usb: typec: tcpm: set initial svdm version based on pd revision") Signed-off-by: Badhri Jagan Sridharan badhri@google.com --- drivers/usb/typec/tcpm/tcpm.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index ab6ed6111ed0..e1c6dffe5f8b 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1580,7 +1580,8 @@ static void svdm_consume_identity(struct tcpm_port *port, const u32 *p, int cnt) port->partner_ident.cert_stat = p[VDO_INDEX_CSTAT]; port->partner_ident.product = product;
- typec_partner_set_identity(port->partner); + if (port->partner) + typec_partner_set_identity(port->partner);
tcpm_log(port, "Identity: %04x:%04x.%04x", PD_IDH_VID(vdo), @@ -1742,6 +1743,9 @@ static void tcpm_register_partner_altmodes(struct tcpm_port *port) struct typec_altmode *altmode; int i;
+ if (!port->partner) + return; + for (i = 0; i < modep->altmodes; i++) { altmode = typec_partner_register_altmode(port->partner, &modep->altmode_desc[i]); @@ -4231,7 +4235,10 @@ static int tcpm_init_vconn(struct tcpm_port *port)
static void tcpm_typec_connect(struct tcpm_port *port) { + struct typec_partner *partner; + if (!port->connected) { + port->connected = true; /* Make sure we don't report stale identity information */ memset(&port->partner_ident, 0, sizeof(port->partner_ident)); port->partner_desc.usb_pd = port->pd_capable; @@ -4241,9 +4248,13 @@ static void tcpm_typec_connect(struct tcpm_port *port) port->partner_desc.accessory = TYPEC_ACCESSORY_AUDIO; else port->partner_desc.accessory = TYPEC_ACCESSORY_NONE; - port->partner = typec_register_partner(port->typec_port, - &port->partner_desc); - port->connected = true; + partner = typec_register_partner(port->typec_port, &port->partner_desc); + if (IS_ERR(partner)) { + dev_err(port->dev, "Failed to register partner (%ld)\n", PTR_ERR(partner)); + return; + } + + port->partner = partner; typec_partner_set_usb_power_delivery(port->partner, port->partner_pd); } } @@ -4323,9 +4334,11 @@ static void tcpm_typec_disconnect(struct tcpm_port *port) port->plug_prime = NULL; port->cable = NULL; if (port->connected) { - typec_partner_set_usb_power_delivery(port->partner, NULL); - typec_unregister_partner(port->partner); - port->partner = NULL; + if (port->partner) { + typec_partner_set_usb_power_delivery(port->partner, NULL); + typec_unregister_partner(port->partner); + port->partner = NULL; + } port->connected = false; } } @@ -4549,6 +4562,9 @@ static enum typec_cc_status tcpm_pwr_opmode_to_rp(enum typec_pwr_opmode opmode)
static void tcpm_set_initial_svdm_version(struct tcpm_port *port) { + if (!port->partner) + return; + switch (port->negotiated_rev) { case PD_REV30: break;
base-commit: 3f12222a4bebeb13ce06ddecc1610ad32fa835dd