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Fencer Vulns
medium 4.7

CVE-2024-35977 json

platform/chrome: cros_ec_uart: properly fix race condition

published 2024-05-20 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-35695

cvss
4.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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().

Patch / fix

  • Linux Linux 6.6.28, 6.8.7, 6.9
  • linux Debian 14, Debian 13 6.8.9-1

debian advisories DEBIAN-CVE-2024-35977

  • linux Ubuntu 24.04 LTS 6.8.0-38.38
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1011.12
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1010.11
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1006.9
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1008.8
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1010.10
  • linux-intel Ubuntu 24.04 LTS 6.8.0-1007.14
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1007.7

ubuntu advisories UBUNTU-CVE-2024-35977

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-livepatch-MICRO-6-0-RT_Update_5 Linux Micro 6.1, Linux Micro 6.0 1-1.1
  • kernel-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source Linux Micro 6.0 6.4.0-18.1
  • kernel-default Linux Micro 6.0 6.4.0-18.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-18.1

suse advisories SUSE-SU-2025:20166-1SUSE-SU-2025:20249-1SUSE-SU-2025:20028-1SUSE-SU-2025:20008-1SUSE-SU-2024:2973-1SUSE-SU-2024:2203-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-35977 updated cvss 5.5

kernel: platform/chrome: cros_ec_uart: properly fix race condition

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
  • CWE-476 NULL Pointer Dereference
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.