On Sat, Apr 27, 2024 at 08:28:12PM +0000, Badhri Jagan Sridharan wrote:
typec_register_partner() does not guarantee partner registration to always succeed. In the event of failure, port->partner is set to the error value or NULL. Given that port->partner validity is not checked, this results in the following crash:
Unable to handle kernel NULL pointer dereference at virtual address xx pc : run_state_machine+0x1bc8/0x1c08 lr : run_state_machine+0x1b90/0x1c08 .. Call trace: run_state_machine+0x1bc8/0x1c08 tcpm_state_machine_work+0x94/0xe4 kthread_worker_fn+0x118/0x328 kthread+0x1d0/0x23c ret_from_fork+0x10/0x20
To prevent the crash, check for port->partner validity before derefencing it in all the call sites.
Cc: stable@vger.kernel.org Fixes: c97cd0b4b54e ("usb: typec: tcpm: set initial svdm version based on pd revision") Signed-off-by: Badhri Jagan Sridharan badhri@google.com
drivers/usb/typec/tcpm/tcpm.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-)
Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org