In the Linux kernel, the following vulnerability has been resolved: tty: serial: fsl_lpuart: mark last busy before uart_add_one_port With "earlycon initcall_debug=1 loglevel=8" in bootargs, kernel sometimes boot hang. It is because normal console still is not ready, but runtime suspend is called, so early console putchar will hang in waiting TRDE set in UARTSTAT. The lpuart driver has auto suspend delay set to 3000ms, but during uart_add_one_port, a child device serial ctrl will added and probed with its pm runtime enabled(see serial_ctrl.c). The runtime suspend call path is: device_add |-> bus_probe_device |->device_initial_probe |->__device_attach |-> pm_runtime_get_sync(dev->parent); |-> pm_request_idle(dev); |-> pm_runtime_put(dev->parent); So in the end, before normal console ready, the lpuart get runtime suspended. And earlycon putchar will hang. To address the issue, mark last busy just after pm_runtime_enable, three seconds is long enough to switch from bootconsole to normal console.
History

Thu, 19 Sep 2024 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 4.0, 'vector': 'CVSS:3.1/AV:P/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}

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'}


Sun, 15 Sep 2024 19:00:00 +0000

Type Values Removed Values Added
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': 4.0, 'vector': 'CVSS:3.1/AV:P/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Fri, 13 Sep 2024 23:30:00 +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

Low


Fri, 13 Sep 2024 06:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: tty: serial: fsl_lpuart: mark last busy before uart_add_one_port With "earlycon initcall_debug=1 loglevel=8" in bootargs, kernel sometimes boot hang. It is because normal console still is not ready, but runtime suspend is called, so early console putchar will hang in waiting TRDE set in UARTSTAT. The lpuart driver has auto suspend delay set to 3000ms, but during uart_add_one_port, a child device serial ctrl will added and probed with its pm runtime enabled(see serial_ctrl.c). The runtime suspend call path is: device_add |-> bus_probe_device |->device_initial_probe |->__device_attach |-> pm_runtime_get_sync(dev->parent); |-> pm_request_idle(dev); |-> pm_runtime_put(dev->parent); So in the end, before normal console ready, the lpuart get runtime suspended. And earlycon putchar will hang. To address the issue, mark last busy just after pm_runtime_enable, three seconds is long enough to switch from bootconsole to normal console.
Title tty: serial: fsl_lpuart: mark last busy before uart_add_one_port
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-09-13T06:27:33.085Z

Updated: 2024-09-15T17:58:04.947Z

Reserved: 2024-09-11T15:12:18.252Z

Link: CVE-2024-46706

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2024-09-13T07:15:05.560

Modified: 2024-09-19T17:51:07.670

Link: CVE-2024-46706

cve-icon Redhat

Severity : Low

Publid Date: 2024-09-13T00:00:00Z

Links: CVE-2024-46706 - Bugzilla