CVE-2023-53176
Description
From CVE.org
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.
Statement
This vulnerability is rated Moderate for Red Hat Enterprise Linux. A privileged local attacker (ex. with CAP_SYS_ADMIN privileges) could cause a denial of service by unbinding a serial port hardware-specific 8250 driver, leading to a kernel oops.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.4 | 5.5 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | High | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | High |
| Integrity Impact | None | None | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
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