CVE-2024-36899: Linux kernel · gpiolib: cdev: Fix use after free in lineinfo_changed_notify
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.0 High · fixed in 5.15.0-1080.87~20.04.1 : patch Linux kernel soon.
Data as of 12 Nov 2026, 19:04 UTC
- Patch
- Available – fixed in 5.15.0-1080.87~20.04.1, 5.15.0-1086.95~20.04.1, 5.15.0-1081.90~20.04.1 +49
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 May 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7407-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2024-36899 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-36899 (opens in a new tab)
- git.kernel.org/linus/02f6b0e1ec7e0e7d059dddc893645816552039da (opens in a new tab)
- git.kernel.org/stable/c/95ca7c90eaf5ea8a8460536535101e3e81160e2a (opens in a new tab)
- git.kernel.org/stable/c/ca710b5f40b8b16fdcad50bebd47f50e4c62d239 (opens in a new tab)
- git.kernel.org/stable/c/02f6b0e1ec7e0e7d059dddc893645816552039da (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7407-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7421-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7458-1 (opens in a new tab)