From: Badhri Jagan Sridharan badhri@google.com

commit ae11f04b452b5205536e1c02d31f8045eba249dd upstream.

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 Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Link: https://lore.kernel.org/r/20240427202812.3435268-1-badhri@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [Sherry: bp to 5.15.y, minor conflicts due to missing commit: 8203d26905ee ("usb: typec: tcpm: Register USB Power Delivery Capabilities"). Ignore the the part typec_partner_set_usb_power_delivery() which is not in 5.15.y.] Signed-off-by: Sherry Yang sherry.yang@oracle.com --- This is a fix for CVE-2024-36893. --- drivers/usb/typec/tcpm/tcpm.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 5a5886cb0c00..2104bb6e61f5 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1471,7 +1471,8 @@ 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), @@ -1559,6 +1560,9 @@ 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]); @@ -3577,7 +3581,10 @@ 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; @@ -3587,9 +3594,13 @@ 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; } }

@@ -3658,8 +3669,10 @@ static int tcpm_src_attach(struct tcpm_port *port) static void tcpm_typec_disconnect(struct tcpm_port *port) { if (port->connected) { - typec_unregister_partner(port->partner); - port->partner = NULL; + if (port->partner) { + typec_unregister_partner(port->partner); + port->partner = NULL; + } port->connected = false; } } @@ -3868,6 +3881,9 @@ 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;