CVE-2024-26932

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

usb: typec: tcpm: fix double-free issue in tcpm_port_unregister_pd()

When unregister pd capabilitie in tcpm, KASAN will capture below double -free issue. The root cause is the same capabilitiy will be kfreed twice, the first time is kfreed by pd_capabilities_release() and the second time is explicitly kfreed by tcpm_port_unregister_pd().

[ 3.988059] BUG: KASAN: double-free in tcpm_port_unregister_pd+0x1a4/0x3dc [ 3.995001] Free of addr ffff0008164d3000 by task kworker/u16:0/10 [ 4.001206] [ 4.002712] CPU: 2 PID: 10 Comm: kworker/u16:0 Not tainted 6.8.0-rc5-next-20240220-05616-g52728c567a55 #53 [ 4.012402] Hardware name: Freescale i.MX8QXP MEK (DT) [ 4.017569] Workqueue: events_unbound deferred_probe_work_func [ 4.023456] Call trace: [ 4.025920] dump_backtrace+0x94/0xec [ 4.029629] show_stack+0x18/0x24 [ 4.032974] dump_stack_lvl+0x78/0x90 [ 4.036675] print_report+0xfc/0x5c0 [ 4.040289] kasan_report_invalid_free+0xa0/0xc0 [ 4.044937] __kasan_slab_free+0x124/0x154 [ 4.049072] kfree+0xb4/0x1e8 [ 4.052069] tcpm_port_unregister_pd+0x1a4/0x3dc [ 4.056725] tcpm_register_port+0x1dd0/0x2558 [ 4.061121] tcpci_register_port+0x420/0x71c [ 4.065430] tcpci_probe+0x118/0x2e0

To fix the issue, this will remove kree() from tcpm_port_unregister_pd().

Weakness

The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/242e425ed580b2f4dbcb86c8fc03a410a4084a69
• https://git.kernel.org/stable/c/b63f90487bdf93a4223ce7853d14717e9d452856