In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix PM usage_count for console handover When console is enabled, univ8250_console_setup() calls serial8250_console_setup() before .dev is set to uart_port. Therefore, it will not call pm_runtime_get_sync(). Later, when the actual driver is going to take over univ8250_console_exit() is called. As .dev is already set, serial8250_console_exit() makes pm_runtime_put_sync() call with usage count being zero triggering PM usage count warning (extra debug for univ8250_console_setup(), univ8250_console_exit(), and serial8250_register_ports()): [ 0.068987] univ8250_console_setup ttyS0 nodev [ 0.499670] printk: console [ttyS0] enabled [ 0.717955] printk: console [ttyS0] printing thread started [ 1.960163] serial8250_register_ports assigned dev for ttyS0 [ 1.976830] printk: console [ttyS0] disabled [ 1.976888] printk: console [ttyS0] printing thread stopped [ 1.977073] univ8250_console_exit ttyS0 usage:0 [ 1.977075] serial8250 serial8250: Runtime PM usage count underflow! [ 1.977429] dw-apb-uart.6: ttyS0 at MMIO 0x4010006000 (irq = 33, base_baud = 115200) is a 16550A [ 1.977812] univ8250_console_setup ttyS0 usage:2 [ 1.978167] printk: console [ttyS0] printing thread started [ 1.978203] printk: console [ttyS0] enabled To fix the issue, call pm_runtime_get_sync() in serial8250_register_ports() as soon as .dev is set for an uart_port if it has console enabled. This problem became apparent only recently because 82586a721595 ("PM: runtime: Avoid device usage count underflows") added the warning printout. I confirmed this problem also occurs with v5.18 (w/o the warning printout, obviously).

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

No data.

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/190ce5cdc55d1b66ea582ac2be6fd5a72e3cc486 cve-icon cve-icon
https://git.kernel.org/stable/c/5df66302f03f87ae8953785a882d78e911f00c55 cve-icon cve-icon
https://git.kernel.org/stable/c/d9cb6fabc90102f9e61fe35bd0160db88f4f53b4 cve-icon cve-icon
https://git.kernel.org/stable/c/f9b11229b79c0fb2100b5bb4628a101b1d37fbf6 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025022614-CVE-2022-49613-32fa@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2022-49613 cve-icon
https://www.cve.org/CVERecord?id=CVE-2022-49613 cve-icon
History

Thu, 01 May 2025 02:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-99
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

 cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}

Thu, 27 Feb 2025 13:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Wed, 26 Feb 2025 02:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix PM usage_count for console handover When console is enabled, univ8250_console_setup() calls serial8250_console_setup() before .dev is set to uart_port. Therefore, it will not call pm_runtime_get_sync(). Later, when the actual driver is going to take over univ8250_console_exit() is called. As .dev is already set, serial8250_console_exit() makes pm_runtime_put_sync() call with usage count being zero triggering PM usage count warning (extra debug for univ8250_console_setup(), univ8250_console_exit(), and serial8250_register_ports()): [ 0.068987] univ8250_console_setup ttyS0 nodev [ 0.499670] printk: console [ttyS0] enabled [ 0.717955] printk: console [ttyS0] printing thread started [ 1.960163] serial8250_register_ports assigned dev for ttyS0 [ 1.976830] printk: console [ttyS0] disabled [ 1.976888] printk: console [ttyS0] printing thread stopped [ 1.977073] univ8250_console_exit ttyS0 usage:0 [ 1.977075] serial8250 serial8250: Runtime PM usage count underflow! [ 1.977429] dw-apb-uart.6: ttyS0 at MMIO 0x4010006000 (irq = 33, base_baud = 115200) is a 16550A [ 1.977812] univ8250_console_setup ttyS0 usage:2 [ 1.978167] printk: console [ttyS0] printing thread started [ 1.978203] printk: console [ttyS0] enabled To fix the issue, call pm_runtime_get_sync() in serial8250_register_ports() as soon as .dev is set for an uart_port if it has console enabled. This problem became apparent only recently because 82586a721595 ("PM: runtime: Avoid device usage count underflows") added the warning printout. I confirmed this problem also occurs with v5.18 (w/o the warning printout, obviously).
Title serial: 8250: Fix PM usage_count for console handover
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-02-26T02:23:34.739Z

Updated: 2025-05-04T08:41:48.842Z

Reserved: 2025-02-26T02:21:30.418Z

Link: CVE-2022-49613

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-02-26T07:01:36.747

Modified: 2025-02-26T07:01:36.747

Link: CVE-2022-49613

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-02-26T00:00:00Z

Links: CVE-2022-49613 - Bugzilla