From 4987daf86c152ff882d51572d154ad12e4ff3a4b Mon Sep 17 00:00:00 2001
From: Jimmy Hu <hhhuuu@google.com>
Date: Fri, 20 Oct 2023 01:21:32 +0000
Subject: [PATCH] usb: typec: tcpm: Fix NULL pointer dereference in tcpm_pd_svdm()
Git-commit: 4987daf86c152ff882d51572d154ad12e4ff3a4b
Patch-mainline: v6.7-rc1
References: git-fixes
It is possible that typec_register_partner() returns ERR_PTR on failure.
When port->partner is an error, a NULL pointer dereference may occur as
shown below.
[91222.095236][ T319] typec port0: failed to register partner (-17)
...
[91225.061491][ T319] Unable to handle kernel NULL pointer dereference
at virtual address 000000000000039f
[91225.274642][ T319] pc : tcpm_pd_data_request+0x310/0x13fc
[91225.274646][ T319] lr : tcpm_pd_data_request+0x298/0x13fc
[91225.308067][ T319] Call trace:
[91225.308070][ T319] tcpm_pd_data_request+0x310/0x13fc
[91225.308073][ T319] tcpm_pd_rx_handler+0x100/0x9e8
[91225.355900][ T319] kthread_worker_fn+0x178/0x58c
[91225.355902][ T319] kthread+0x150/0x200
[91225.355905][ T319] ret_from_fork+0x10/0x30
Add a check for port->partner to avoid dereferencing a NULL pointer.
Fixes: 5e1d4c49fbc8 ("usb: typec: tcpm: Determine common SVDM Version")
Cc: stable@vger.kernel.org
Signed-off-by: Jimmy Hu <hhhuuu@google.com>
Link: https://lore.kernel.org/r/20231020012132.100960-1-hhhuuu@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/usb/typec/tcpm/tcpm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 1c7e8dc5282d..058d5b853b57 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -1625,6 +1625,9 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
if (PD_VDO_VID(p[0]) != USB_SID_PD)
break;
+ if (IS_ERR_OR_NULL(port->partner))
+ break;
+
if (PD_VDO_SVDM_VER(p[0]) < svdm_version) {
typec_partner_set_svdm_version(port->partner,
PD_VDO_SVDM_VER(p[0]));
--
2.35.3