In the Linux kernel, the following vulnerability has been resolved: serial: core: do fallible allocations before the console can be registered serial_core_add_one_port() allocates uport->tty_groups after uart_configure_port(), which ma…

Overview

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

serial: core: do fallible allocations before the console can be registered

serial_core_add_one_port() allocates uport->tty_groups after uart_configure_port(), which may register the console. If the allocation fails, the driver unwinds the port while its console remains registered. The earlier uport->name allocation has a related failure path that leaves state->uart_port linked to a port being freed.

Failslab reproduced a NULL dereference in PL011 console output and a KASAN use-after-free in i.MX console output after failed binds.

Allocate the name and tty_groups before linking the port and configuring it. Reserve space for the optional driver attribute group because config_port() may populate uport->attr_group during configuration.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.