From e44189455c62469eb91d383ce9103d54c1f807a3 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 11 Nov 2024 14:08:06 +0300 Subject: [PATCH] usb: typec: fix potential array underflow in ucsi_ccg_sync_control() commit e56aac6e5a25630645607b6856d4b2a17b2311a5 upstream. 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 Reviewed-by: Heikki Krogerus Link: https://lore.kernel.org/r/c69ef0b3-61b0-4dde-98dd-97b97f81d912@stanley.mountain Signed-off-by: Greg Kroah-Hartman [ 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 6.1.y accordingly. ] Signed-off-by: Bin Lan Signed-off-by: He Zhe Signed-off-by: Greg Kroah-Hartman --- 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 8e500fe41e785..4801d783bd0ca 100644 --- a/drivers/usb/typec/ucsi/ucsi_ccg.c +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c @@ -585,6 +585,10 @@ 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); } @@ -600,6 +604,7 @@ 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;