linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jimmy Hu <hhhuuu@google.com>
To: linux@roeck-us.net, heikki.krogerus@linux.intel.com,
	gregkh@linuxfoundation.org
Cc: kyletso@google.com, badhri@google.com, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, Jimmy Hu <hhhuuu@google.com>
Subject: [PATCH] usb: typec: tcpm: Fix NULL pointer dereference in tcpm_pd_svdm()
Date: Thu, 19 Oct 2023 06:06:16 +0000	[thread overview]
Message-ID: <20231019060616.1988631-1-hhhuuu@google.com> (raw)

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")
Signed-off-by: Jimmy Hu <hhhuuu@google.com>
---
 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 6e843c511b85..792ec4ac7d8d 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]));
-- 
2.42.0.655.g421f12c284-goog


             reply	other threads:[~2023-10-19  6:06 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-19  6:06 Jimmy Hu [this message]
2023-10-19  8:23 ` [PATCH] usb: typec: tcpm: Fix NULL pointer dereference in tcpm_pd_svdm() Heikki Krogerus
2023-10-20  1:24   ` Jimmy Hu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20231019060616.1988631-1-hhhuuu@google.com \
    --to=hhhuuu@google.com \
    --cc=badhri@google.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=heikki.krogerus@linux.intel.com \
    --cc=kyletso@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=linux@roeck-us.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).