CVE-2024-36899gpiolib: cdev: Fix use after free in lineinfo_changed_notify

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.

Timeline

Scores

EPSS (exploitation in 30 days)

0.18% · top 92% of all CVEs (14 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.0.

Affected products

• Linux · Linux

  • affected 51c1064e82e77b39a49889287ca50709303e2f26 – < 2dfbb920a89bdc58087672ad5325dc6c588b6860
  • affected 51c1064e82e77b39a49889287ca50709303e2f26 – < 2d008d4961b039d2edce8976289773961b7e5fb5
  • affected 51c1064e82e77b39a49889287ca50709303e2f26 – < d38c49f7bdf14381270736299e2ff68ec248a017
  • affected 51c1064e82e77b39a49889287ca50709303e2f26 – < 95ca7c90eaf5ea8a8460536535101e3e81160e2a
  • affected 51c1064e82e77b39a49889287ca50709303e2f26 – < ca710b5f40b8b16fdcad50bebd47f50e4c62d239
  • affected 51c1064e82e77b39a49889287ca50709303e2f26 – < 02f6b0e1ec7e0e7d059dddc893645816552039da

• Linux · Linux

  • affected 5.7
  • unaffected < 5.7
  • unaffected 5.10.234 – ≤ 5.10.*
  • unaffected 5.15.177 – ≤ 5.15.*
  • unaffected 6.1.127 – ≤ 6.1.*
  • unaffected 6.6.31 – ≤ 6.6.*
  • unaffected 6.8.10 – ≤ 6.8.*
  • unaffected 6.9 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2024-36388 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2024-36899](https://cveledger.app/badge/CVE-2024-36899.svg)](https://cveledger.app/cve/CVE-2024-36899)

Record last updated 15 Oct 2026, 00:42 UTC.