CVE-2024-36893

In the Linux kernel, the following vulnerability has been resolved:

usb: typec: tcpm: Check for port partner validity before consuming it

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.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/2a07e6f0ad8a6e504a3912cfe8dc859b7d0740a5
• https://git.kernel.org/stable/c/789326cafbd1f67f424436b6bc8bdb887a364637
• https://git.kernel.org/stable/c/ae11f04b452b5205536e1c02d31f8045eba249dd
• https://git.kernel.org/stable/c/d56d2ca03cc22123fd7626967d096d8661324e57
• https://git.kernel.org/stable/c/fc2b655cb6dd2b381f1f284989721002e39b6b77