CVE-2024-36899

Advisory lineage Upstream: 0 Downstream: 120
Modified
Published: 30 May 2024, 15:29
Last modified:12 May 2026, 11:53

Vulnerability Summary

Overall Risk (default)
medium
28/100
CVSS Score
7 HIGH
v3.1 (nvd)
EPSS Score
<0.01% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

30 May 2024, 15:29
Published
Vulnerability first disclosed
12 May 2026, 11:53
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: gpiolib: cdev: Fix use after free in lineinfo_changed_notify The use-after-free issue occurs as follows: when the GPIO chip device file is being closed by invoking gpio_chrdev_release(), watched_lines is freed by bitmap_free(), but the unregistration of lineinfo_changed_nb notifier chain failed due to waiting write rwsem. Additionally, one of the GPIO chip's lines is also in the release process and holds the notifier chain's read rwsem. Consequently, a race condition leads to the use-after-free of watched_lines. Here is the typical stack when issue happened: [free] gpio_chrdev_release() --> bitmap_free(cdev->watched_lines) <-- freed --> blocking_notifier_chain_unregister() --> down_write(&nh->rwsem) <-- waiting rwsem --> __down_write_common() --> rwsem_down_write_slowpath() --> schedule_preempt_disabled() --> schedule() [use] st54spi_gpio_dev_release() --> gpio_free() --> gpiod_free() --> gpiod_free_commit() --> gpiod_line_state_notify() --> blocking_notifier_call_chain() --> down_read(&nh->rwsem); <-- held rwsem --> notifier_call_chain() --> lineinfo_changed_notify() --> test_bit(xxxx, cdev->watched_lines) <-- use after free The side effect of the use-after-free issue is that a GPIO line event is being generated for userspace where it shouldn't. However, since the chrdev is being closed, userspace won't have the chance to read that event anyway. To fix the issue, call the bitmap_free() function after the unregistration of lineinfo_changed_nb notifier chain.

CVSS Metrics

  • v3.1•HIGH•Score: 7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 1%

Techniques & Countermeasures

  • CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • linux•linux

    ≥ 51c1064e82e77b39a49889287ca50709303e2f26, < 2dfbb920a89bdc58087672ad5325dc6c588b6860 | ≥ 51c1064e82e77b39a49889287ca50709303e2f26, < 2d008d4961b039d2edce8976289773961b7e5fb5 | ≥ 51c1064e82e77b39a49889287ca50709303e2f26, < d38c49f7bdf14381270736299e2ff68ec248a017 | ≥ 51c1064e82e77b39a49889287ca50709303e2f26, < 95ca7c90eaf5ea8a8460536535101e3e81160e2a | ≥ 51c1064e82e77b39a49889287ca50709303e2f26, < ca710b5f40b8b16fdcad50bebd47f50e4c62d239 | ≥ 51c1064e82e77b39a49889287ca50709303e2f26, < 02f6b0e1ec7e0e7d059dddc893645816552039da | 5.7

  • linux•linux_kernel

    ≥ 5.7, < 6.6.31 | ≥ 6.7, < 6.8.10 | 6.9:rc1 | 6.9:rc2 | 6.9:rc3 | 6.9:rc4 | 6.9:rc5 | 6.9:rc6 | 6.9:rc7

References (9)