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.
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Ubuntu USN |
USN-7154-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7155-1 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-7156-1 | Linux kernel (GKE) vulnerabilities |
Ubuntu USN |
USN-7154-2 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7196-1 | Linux kernel (Azure) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Wed, 16 Jul 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
|
epss
|
Sun, 29 Sep 2024 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
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
|
cvssV3_1
|
Sun, 15 Sep 2024 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Fri, 13 Sep 2024 23:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
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 |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T09:32:21.349Z
Reserved: 2024-09-11T15:12:18.252Z
Link: CVE-2024-46706
Updated: 2024-09-29T15:02:53.727Z
Status : Analyzed
Published: 2024-09-13T07:15:05.560
Modified: 2024-09-19T17:51:07.670
Link: CVE-2024-46706
OpenCVE Enrichment
No data.
Ubuntu USN