The Smatch checker flags svdm_version being uninitialized for Discover Identity Messages within tcpm_pd_svdm for the CMDT_INIT case. Cable plugs cannot initialize SVDM commands, however a port partner that isn't allowed to communicate over SOP' could, which would result in the CMDT_INIT block running for a received SOP' message. First, initialize svdm_version for the TCPC_TX_SOP_PRIME case. If the svdm_version returns as an error, we expect the received svdm to be the result of Discover Identity that updates the value accordingly. Next, drop all SOP' messages of type CMDT_INIT within tcpm_pd_svdm. Finally, remove redundant call that assigns modep and pdev. Smatch will raise an uninitialized symbol error over modep_prime and pdev_prime, but both the assignment and use of these variables are guarded behind a check for rx_sop_type == TCPC_TX_SOP_PRIME. Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Closes: https://lore.kernel.org/all/a432603b-b801-4001-b309-247dded707d3@moroto.mountain/ Fixes: fb7ff25ae433 ("usb: typec: tcpm: add discover identity support for SOP'") Signed-off-by: RD Babiera <rdbabiera@xxxxxxxxxx> --- drivers/usb/typec/tcpm/tcpm.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index d975fc525eac..55c438c62203 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1878,11 +1878,6 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, tcpm_log(port, "Rx VDM cmd 0x%x type %d cmd %d len %d", p[0], cmd_type, cmd, cnt); - modep = &port->mode_data; - - pdev = typec_match_altmode(port->partner_altmode, ALTMODE_DISCOVERY_MAX, - PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0])); - switch (rx_sop_type) { case TCPC_TX_SOP_PRIME: modep_prime = &port->mode_data_prime; @@ -1890,11 +1885,13 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, ALTMODE_DISCOVERY_MAX, PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0])); - if (!IS_ERR_OR_NULL(port->cable)) { - svdm_version = typec_get_cable_svdm_version(typec); - if (PD_VDO_SVDM_VER(p[0]) < svdm_version) - typec_cable_set_svdm_version(port->cable, svdm_version); - } + svdm_version = typec_get_cable_svdm_version(typec); + /* + * Update SVDM version if cable was discovered before port partner. + */ + if (!IS_ERR_OR_NULL(port->cable) && + PD_VDO_SVDM_VER(p[0]) < svdm_version) + typec_cable_set_svdm_version(port->cable, svdm_version); break; case TCPC_TX_SOP: modep = &port->mode_data; @@ -1920,6 +1917,15 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, switch (cmd_type) { case CMDT_INIT: + /* + * Only the port or port partner is allowed to initialize SVDM + * commands over SOP'. In case the port partner initializes a + * sequence when it is not allowed to send SOP' messages, drop + * the message should the TCPM port try to process it. + */ + if (rx_sop_type == TCPC_TX_SOP_PRIME) + return 0; + switch (cmd) { case CMD_DISCOVER_IDENT: if (PD_VDO_VID(p[0]) != USB_SID_PD) base-commit: 3bf0514dc6f36f81ee11b1becd977cb87b4c90c6 -- 2.44.0.rc0.258.g7320e95886-goog
