From 7e8fa789edc46cab549badfc8ffd73ca1ed10e04 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] usb: typec: fix potential array underflow in ucsi_ccg_sync_control() BugLink: https://bugs.launchpad.net/bugs/2101915 [ 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 Reviewed-by: Heikki Krogerus Link: https://lore.kernel.org/r/c69ef0b3-61b0-4dde-98dd-97b97f81d912@stanley.mountain Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin [koichiroden: adjusted patch due to missing commits: 13f2ec3115c8 ("usb: typec: ucsi: simplify command sending API") 584e8df58942 ("usb: typec: ucsi: extract common code for command handling")] CVE-2024-53203 Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- drivers/usb/typec/ucsi/ucsi_ccg.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c index 5fefd191e34b..f02801dab6fd 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 err_clear_bit; + } con = &uc->ucsi->connector[con_index - 1]; ucsi_ccg_update_set_new_cam_cmd(uc, con, (u64 *)val); }