4987daf86c
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: 5e1d4c49fb ("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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.