CVE-2024-35977

platform/chrome: cros_ec_uart: properly fix race condition

4.7 MediumFix available

In the Linux kernel, the following vulnerability has been resolved:

platform/chrome: cros_ec_uart: properly fix race condition

The cros_ec_uart_probe() function calls devm_serdev_device_open() before it calls serdev_device_set_client_ops(). This can trigger a NULL pointer dereference:

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
 <TASK>
 ...
 ? ttyport_receive_buf

A simplified version of crashing code is as follows:

static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
                                                  const u8 *data,
                                                  size_t count)
{
        struct serdev_device *serdev = ctrl->serdev;

        if (!serdev || !serdev->ops->receive_buf) // CRASH!
            return 0;

        return serdev->ops->receive_buf(serdev, data, count);
}

It assumes that if SERPORT_ACTIVE is set and serdev exists, serdev->ops will also exist. This conflicts with the existing cros_ec_uart_probe() logic, as it first calls devm_serdev_device_open() (which sets SERPORT_ACTIVE), and only later sets serdev->ops via serdev_device_set_client_ops().

Commit 01f95d42b8f4 ("platform/chrome: cros_ec_uart: fix race condition") attempted to fix a similar race condition, but while doing so, made the window of error for this race condition to happen much wider.

Attempt to fix the race condition again, making sure we fully setup before calling devm_serdev_device_open().

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: High
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.17%Up 0.1 points since May 21, 2024

What each source reports

NVD Score used 4.7

In the Linux kernel, the following vulnerability has been resolved:

platform/chrome: cros_ec_uart: properly fix race condition

The cros_ec_uart_probe() function calls devm_serdev_device_open() before it calls serdev_device_set_client_ops(). This can trigger a NULL pointer dereference:

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
 <TASK>
 ...
 ? ttyport_receive_buf

A simplified version of crashing code is as follows:

static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
                                                  const u8 *data,
                                                  size_t count)
{
        struct serdev_device *serdev = ctrl->serdev;

        if (!serdev || !serdev->ops->receive_buf) // CRASH!
            return 0;

        return serdev->ops->receive_buf(serdev, data, count);
}

Attempt to fix the race condition again, making sure we fully setup before calling devm_serdev_device_open().

Record: CVE-2024-35977
CVSS 3.1: 4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-362, CWE-476
Updated: 2026-11-02

CVE List No score

platform/chrome: cros_ec_uart: properly fix race condition

In the Linux kernel, the following vulnerability has been resolved:

platform/chrome: cros_ec_uart: properly fix race condition

The cros_ec_uart_probe() function calls devm_serdev_device_open() before it calls serdev_device_set_client_ops(). This can trigger a NULL pointer dereference:

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
 <TASK>
 ...
 ? ttyport_receive_buf

A simplified version of crashing code is as follows:

static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
                                                  const u8 *data,
                                                  size_t count)
{
        struct serdev_device *serdev = ctrl->serdev;

        if (!serdev || !serdev->ops->receive_buf) // CRASH!
            return 0;

        return serdev->ops->receive_buf(serdev, data, count);
}

Attempt to fix the race condition again, making sure we fully setup before calling devm_serdev_device_open().

Record: CVE-2024-35977
Updated: 2026-11-02

EUVDEUVD-2024-35695 No score

In the Linux kernel, the following vulnerability has been resolved:

platform/chrome: cros_ec_uart: properly fix race condition

The cros_ec_uart_probe() function calls devm_serdev_device_open() before it calls serdev_device_set_client_ops(). This can trigger a NULL pointer dereference:

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
 <TASK>
 ...
 ? ttyport_receive_buf

A simplified version of crashing code is as follows:

static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
                                                  const u8 *data,
                                                  size_t count)
{
        struct serdev_device *serdev = ctrl->serdev;

        if (!serdev || !serdev->ops->receive_buf) // CRASH!
            return 0;

        return serdev->ops->receive_buf(serdev, data, count);
}

Attempt to fix the race condition again, making sure we fully setup before calling devm_serdev_device_open().

Record: EUVD-2024-35695
Updated: 2026-11-02

GitHub AdvisoriesGHSA-r3pw-96wv-8pj5 4.7

In the Linux kernel, the following vulnerability has been resolved: platform/chrome:...

In the Linux kernel, the following vulnerability has been resolved:

platform/chrome: cros_ec_uart: properly fix race condition

The cros_ec_uart_probe() function calls devm_serdev_device_open() before it calls serdev_device_set_client_ops(). This can trigger a NULL pointer dereference:

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
 <TASK>
 ...
 ? ttyport_receive_buf

A simplified version of crashing code is as follows:

static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
                                                  const u8 *data,
                                                  size_t count)
{
        struct serdev_device *serdev = ctrl->serdev;

        if (!serdev || !serdev->ops->receive_buf) // CRASH!
            return 0;

        return serdev->ops->receive_buf(serdev, data, count);
}

Attempt to fix the race condition again, making sure we fully setup before calling devm_serdev_device_open().

Record: GHSA-r3pw-96wv-8pj5
CVSS 3.1: 4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-362
Updated: 2026-11-02

OSVBELL-CVE-2024-35977 4.7

Record: BELL-CVE-2024-35977
CVSS 3.1: 4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2024-35977 4.7

In the Linux kernel, the following vulnerability has been resolved: platform/chrome: cros_ec_uart: properly fix race condition The cros_ec_uart_probe() function calls devm_serdev_device_open() before it calls serdev_device_set_client_ops(). This can trigger a NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: <TASK> ... ? ttyport_receive_buf A simplified version of crashing code is as follows: static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl, const u8 *data, size_t count) { struct serdev_device *serdev = ctrl->serdev; if (!serdev || !serdev->ops->receive_buf) // CRASH! return 0; return serdev->ops->receive_buf(serdev, data, count); } It assumes that if SERPORT_ACTIVE is set and serdev exists, serdev->ops will also exist. This conflicts with the existing cros_ec_uart_probe() logic, as it first calls devm_serdev_device_open() (which sets SERPORT_ACTIVE), and only later sets serdev->ops via serdev_device_set_client_ops(). Commit 01f95d42b8f4 ("platform/chrome: cros_ec_uart: fix race condition") attempted to fix a similar race condition, but while doing so, made the window of error for this race condition to happen much wider. Attempt to fix the race condition again, making sure we fully setup before calling devm_serdev_device_open().

Record: DEBIAN-CVE-2024-35977
CVSS 3.1: 4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

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OSVUBUNTU-CVE-2024-35977 4.7

Record: UBUNTU-CVE-2024-35977
CVSS 3.1: 4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSV No score

platform/chrome: cros_ec_uart: properly fix race condition

In the Linux kernel, the following vulnerability has been resolved:

platform/chrome: cros_ec_uart: properly fix race condition

The cros_ec_uart_probe() function calls devm_serdev_device_open() before it calls serdev_device_set_client_ops(). This can trigger a NULL pointer dereference:

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
 <TASK>
 ...
 ? ttyport_receive_buf

A simplified version of crashing code is as follows:

static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
                                                  const u8 *data,
                                                  size_t count)
{
        struct serdev_device *serdev = ctrl->serdev;

        if (!serdev || !serdev->ops->receive_buf) // CRASH!
            return 0;

        return serdev->ops->receive_buf(serdev, data, count);
}

Attempt to fix the race condition again, making sure we fully setup before calling devm_serdev_device_open().

Record: CVE-2024-35977
Updated: 2026-11-02

OSVSUSE-SU-2024:2135-1 No score