From: Dan Carpenter dan.carpenter@linaro.org

[ Upstream commit e56aac6e5a25630645607b6856d4b2a17b2311a5 ]

The "command" variable can be controlled by the user via debugfs. The worry is that if con_index is zero then "&uc->ucsi->connector[con_index - 1]" would be an array underflow.

Fixes: 170a6726d0e2 ("usb: typec: ucsi: add support for separate DP altmode devices") Signed-off-by: Dan Carpenter dan.carpenter@linaro.org Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Link: https://lore.kernel.org/r/c69ef0b3-61b0-4dde-98dd-97b97f81d912@stanley.mount... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [The function ucsi_ccg_sync_write() is renamed to ucsi_ccg_sync_control() in commit 13f2ec3115c8 ("usb: typec: ucsi:simplify command sending API"). Apply this patch to ucsi_ccg_sync_write() in 5.15.y accordingly.] Signed-off-by: Bin Lan bin.lan.cn@windriver.com Signed-off-by: He Zhe zhe.he@windriver.com --- Build test passed. --- drivers/usb/typec/ucsi/ucsi_ccg.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c index fb6211efb5d8..3983bf21a580 100644 --- a/drivers/usb/typec/ucsi/ucsi_ccg.c +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c @@ -573,6 +573,10 @@ static int ucsi_ccg_sync_write(struct ucsi *ucsi, unsigned int offset, uc->has_multiple_dp) { con_index = (uc->last_cmd_sent >> 16) & UCSI_CMD_CONNECTOR_MASK; + if (con_index == 0) { + ret = -EINVAL; + goto unlock; + } con = &uc->ucsi->connector[con_index - 1]; ucsi_ccg_update_set_new_cam_cmd(uc, con, (u64 *)val); } @@ -588,6 +592,7 @@ static int ucsi_ccg_sync_write(struct ucsi *ucsi, unsigned int offset, err_clear_bit: clear_bit(DEV_CMD_PENDING, &uc->flags); pm_runtime_put_sync(uc->dev); +unlock: mutex_unlock(&uc->lock);

return ret;