ghsa-ffrj-g2q4-vf85
Vulnerability from github
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).
{
"affected": [],
"aliases": [
"CVE-2022-49613"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-26T07:01:36Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nserial: 8250: Fix PM usage_count for console handover\n\nWhen console is enabled, univ8250_console_setup() calls\nserial8250_console_setup() before .dev is set to uart_port. Therefore,\nit will not call pm_runtime_get_sync(). Later, when the actual driver\nis going to take over univ8250_console_exit() is called. As .dev is\nalready set, serial8250_console_exit() makes pm_runtime_put_sync() call\nwith usage count being zero triggering PM usage count warning\n(extra debug for univ8250_console_setup(), univ8250_console_exit(), and\nserial8250_register_ports()):\n\n[ 0.068987] univ8250_console_setup ttyS0 nodev\n[ 0.499670] printk: console [ttyS0] enabled\n[ 0.717955] printk: console [ttyS0] printing thread started\n[ 1.960163] serial8250_register_ports assigned dev for ttyS0\n[ 1.976830] printk: console [ttyS0] disabled\n[ 1.976888] printk: console [ttyS0] printing thread stopped\n[ 1.977073] univ8250_console_exit ttyS0 usage:0\n[ 1.977075] serial8250 serial8250: Runtime PM usage count underflow!\n[ 1.977429] dw-apb-uart.6: ttyS0 at MMIO 0x4010006000 (irq = 33, base_baud = 115200) is a 16550A\n[ 1.977812] univ8250_console_setup ttyS0 usage:2\n[ 1.978167] printk: console [ttyS0] printing thread started\n[ 1.978203] printk: console [ttyS0] enabled\n\nTo fix the issue, call pm_runtime_get_sync() in\nserial8250_register_ports() as soon as .dev is set for an uart_port\nif it has console enabled.\n\nThis problem became apparent only recently because 82586a721595 (\"PM:\nruntime: Avoid device usage count underflows\") added the warning\nprintout. I confirmed this problem also occurs with v5.18 (w/o the\nwarning printout, obviously).",
"id": "GHSA-ffrj-g2q4-vf85",
"modified": "2025-10-23T12:31:15Z",
"published": "2025-10-23T12:31:15Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49613"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/190ce5cdc55d1b66ea582ac2be6fd5a72e3cc486"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5df66302f03f87ae8953785a882d78e911f00c55"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d9cb6fabc90102f9e61fe35bd0160db88f4f53b4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f9b11229b79c0fb2100b5bb4628a101b1d37fbf6"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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