From b0e35d56391770258e04e97b206b1e7a4bc9dbe2 Mon Sep 17 00:00:00 2001 From: Amit Sunil Dhamne Date: Fri, 2 May 2025 16:57:03 -0700 Subject: [PATCH] usb: typec: tcpm/tcpci_maxim: Fix bounds check in process_rx() commit 0736299d090f5c6a1032678705c4bc0a9511a3db upstream. Register read of TCPC_RX_BYTE_CNT returns the total size consisting of: PD message (pending read) size + 1 Byte for Frame Type (SOP*) This is validated against the max PD message (`struct pd_message`) size without accounting for the extra byte for the frame type. Note that the struct pd_message does not contain a field for the frame_type. This results in false negatives when the "PD message (pending read)" is equal to the max PD message size. Fixes: 6f413b559f86 ("usb: typec: tcpci_maxim: Chip level TCPC driver") Signed-off-by: Amit Sunil Dhamne Signed-off-by: Badhri Jagan Sridharan Reviewed-by: Kyle Tso Cc: stable Link: https://lore.kernel.org/stable/20250502-b4-new-fix-pd-rx-count-v1-1-e5711ed09b3d%40google.com Reviewed-by: Heikki Krogerus Link: https://lore.kernel.org/r/20250502-b4-new-fix-pd-rx-count-v1-1-e5711ed09b3d@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/tcpm/tcpci_maxim_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/typec/tcpm/tcpci_maxim_core.c b/drivers/usb/typec/tcpm/tcpci_maxim_core.c index 9454b12a073c..e460b956ab71 100644 --- a/drivers/usb/typec/tcpm/tcpci_maxim_core.c +++ b/drivers/usb/typec/tcpm/tcpci_maxim_core.c @@ -145,7 +145,8 @@ static void process_rx(struct max_tcpci_chip *chip, u16 status) return; } - if (count > sizeof(struct pd_message) || count + 1 > TCPC_RECEIVE_BUFFER_LEN) { + if (count > sizeof(struct pd_message) + 1 || + count + 1 > TCPC_RECEIVE_BUFFER_LEN) { dev_err(chip->dev, "Invalid TCPC_RX_BYTE_CNT %d\n", count); return; }