CVE-2023-53176

01/Description

In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Reinit port->pm on port specific driver unbind When we unbind a serial port hardware specific 8250 driver, the generic serial8250 driver takes over the port. After that we see an oops about 10 seconds later. This can produce the following at least on some TI SoCs: Unhandled fault: imprecise external abort (0x1406) Internal error: : 1406 [#1] SMP ARM Turns out that we may still have the serial port hardware specific driver port->pm in use, and serial8250_pm() tries to call it after the port specific driver is gone: serial8250_pm [8250_base] from uart_change_pm+0x54/0x8c [serial_base] uart_change_pm [serial_base] from uart_hangup+0x154/0x198 [serial_base] uart_hangup [serial_base] from __tty_hangup.part.0+0x328/0x37c __tty_hangup.part.0 from disassociate_ctty+0x154/0x20c disassociate_ctty from do_exit+0x744/0xaac do_exit from do_group_exit+0x40/0x8c do_group_exit from __wake_up_parent+0x0/0x1c Let's fix the issue by calling serial8250_set_defaults() in serial8250_unregister_port(). This will set the port back to using the serial8250 default functions, and sets the port->pm to point to serial8250_pm.

02/Affected products

linux: linux kernel

03/References8

• git.kernel.org/stable/c/04e82793f068d2f0ffe62fcea03d007a8cdc16a7 Patch
• git.kernel.org/stable/c/1ba5594739d858e524ff0f398ee1ebfe0a8b9d41 Patch
• git.kernel.org/stable/c/2c86a1305c1406f45ea780d06953c484ea1d9e6e Patch
• git.kernel.org/stable/c/490bf37eaabb0a857ed1ae8e75d8854e41662f1c Patch
• git.kernel.org/stable/c/8e596aed5f2f98cf3e6e98d6fe1d689f4a319308 Patch
• git.kernel.org/stable/c/af4d6dbb1a92ea424ad1ba1d0c88c7fa2345d872 Patch
• git.kernel.org/stable/c/c9e080c3005fd183c56ff8f4d75edb5da0765d2c Patch
• git.kernel.org/stable/c/d5cd2928d31042a7c0a01464f9a8d95be736421d Patch