Description

In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix oops for port->pm on uart_change_pm() Unloading a hardware specific 8250 driver can produce error "Unable to handle kernel paging request at virtual address" about ten seconds after unloading the driver. This happens on uart_hangup() calling uart_change_pm(). Turns out commit 04e82793f068 ("serial: 8250: Reinit port->pm on port specific driver unbind") was only a partial fix. If the hardware specific driver has initialized port->pm function, we need to clear port->pm too. Just reinitializing port->ops does not do this. Otherwise serial8250_pm() will call port->pm() instead of serial8250_do_pm().

References 8

• git.kernel.org https://git.kernel.org/stable/c/0c05493341d6f2097f75f0a5dbb7b53a9e8c5f6c
• git.kernel.org https://git.kernel.org/stable/c/18e27df4f2b4e257c317ba8076f31a888f6cc64b
• git.kernel.org https://git.kernel.org/stable/c/375806616f8c772c33d40e112530887b37c1a816
• git.kernel.org https://git.kernel.org/stable/c/66f3e55960698c874b0598277913b478ecd29573
• git.kernel.org https://git.kernel.org/stable/c/720a297b334e85d34099e83d1f375b92c3efedd6
• git.kernel.org https://git.kernel.org/stable/c/b653289ca6460a6552c8590b75dfa84a0140a46b
• git.kernel.org https://git.kernel.org/stable/c/bd70d0b28010d560a8be96b44fea86fe2ba016ae
• git.kernel.org https://git.kernel.org/stable/c/dfe2aeb226fd5e19b0ee795f4f6ed8bc494c1534

Remediation