In the Linux kernel, the following vulnerability has been resolved: usb: cdc-acm: Check control transfer buffer size before access If the first fragment is shorter than struct usb_cdc_notification, we can’t calculate an expected_size. Log an error and discard the notification instead of reading lengths from memory outside the received data, which can lead to memory corruption when the expected_size decreases between fragments, causing `expected_size – acm->nb_index` to wrap. This issue has been present since the beginning of git history; however, it only leads to memory corruption since commit ea2583529cd1 (“cdc-acm: reassemble fragmented notifications”). A mitigating factor is that acm_ctrl_irq() can only execute after userspace has opened \/dev\/ttyACM*; but if ModemManager is running, ModemManager will do that automatically depending on the USB device’s vendor\/product IDs and its other interfaces.<\/p>\n
https:\/\/git.kernel.org\/stable\/c\/f64079bef6a8a7823358c3f352ea29a617844636<\/a><\/p>\n https:\/\/git.kernel.org\/stable\/c\/e563b01208f4d1f609bcab13333b6c0e24ce6a01<\/a><\/p>\n https:\/\/git.kernel.org\/stable\/c\/7828e9363ac4d23b02419bf2a45b9f1d9fb35646<\/a><\/p>\n https:\/\/git.kernel.org\/stable\/c\/6abb510251e75f875797d8983a830e6731fa281c<\/a><\/p>\n