gpiolib: cdev: Fix use after free in lineinfo_changed_notify
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 10 fixed, 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.7 and later | 5.10.234, 5.15.177, 6.1.127, 6.6.31, 6.8.10, 6.9 | Patch available | CNA |
- Linux VendorLinux Affected 5.7 and later Fixed in 5.10.234, 5.15.177, 6.1.127, 6.6.31, 6.8.10, 6.9 Patch available CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.7 to before 6.6.31; 6.7 to before 6.8.10 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:* | 6.9 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:* | 6.9 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.9:rc3:*:*:*:*:*:* | 6.9 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.9:rc4:*:*:*:*:*:* | 6.9 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.9:rc5:*:*:*:*:*:* | 6.9 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.9:rc6:*:*:*:*:*:* | 6.9 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.9:rc7:*:*:*:*:*:* | 6.9 rc7 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.7 to before 6.6.31; 6.7 to before 6.8.10 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:* Versions 6.9 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:* Versions 6.9 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.9:rc3:*:*:*:*:*:* Versions 6.9 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.9:rc4:*:*:*:*:*:* Versions 6.9 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.9:rc5:*:*:*:*:*:* Versions 6.9 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.9:rc6:*:*:*:*:*:* Versions 6.9 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.9:rc7:*:*:*:*:*:* Versions 6.9 rc7 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.234, 5.15.177, 6.1.127, 6.6.31, 6.8.10, 6.9
Red Hat 3 advisories
- RHSA-2024:6997 Released 2024-09-24 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-427.37.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.37.1.el9_4, kernel-64k-devel-5.14.0-427.37.1.el9_4 +11
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-7.3.0-427.37.1.el9_4, kernel-5.14.0-427.37.1.el9_4, kernel-64k-5.14.0-427.37.1.el9_4 +29
- Red Hat Enterprise Linux CRB (v. 9) kernel-tools-libs-devel-5.14.0-427.37.1.el9_4, libperf-5.14.0-427.37.1.el9_4
- Red Hat Enterprise Linux NFV (v. 9) kernel-rt-5.14.0-427.37.1.el9_4, kernel-rt-core-5.14.0-427.37.1.el9_4, kernel-rt-debug-5.14.0-427.37.1.el9_4 +11
- Red Hat Enterprise Linux RT (v. 9) kernel-rt-5.14.0-427.37.1.el9_4, kernel-rt-core-5.14.0-427.37.1.el9_4, kernel-rt-debug-5.14.0-427.37.1.el9_4 +9
- RHSA-2024:7004 Released 2024-09-24 · Red Hat rating Importantkernel security update
- Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-tools-libs-devel-5.14.0-284.85.1.el9_2
- Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-64k-debug-devel-5.14.0-284.85.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.85.1.el9_2, kernel-64k-devel-5.14.0-284.85.1.el9_2 +10
- Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool-7.0.0-284.85.1.el9_2, kernel-5.14.0-284.85.1.el9_2, kernel-64k-5.14.0-284.85.1.el9_2 +29
- RHSA-2024:7005 Released 2024-09-24 · Red Hat rating Importantkernel-rt security update
- Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt-5.14.0-284.85.1.rt14.370.el9_2, kernel-rt-core-5.14.0-284.85.1.rt14.370.el9_2, kernel-rt-debug-5.14.0-284.85.1.rt14.370.el9_2 +9
- Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt-5.14.0-284.85.1.rt14.370.el9_2, kernel-rt-core-5.14.0-284.85.1.rt14.370.el9_2, kernel-rt-debug-5.14.0-284.85.1.rt14.370.el9_2 +11
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat CodeReady Linux Builder EUS (v.9.2) | Fixed | RHSA-2024:7004 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2024:6997 |
| Red Hat Enterprise Linux AppStream EUS (v.9.2) | Fixed | RHSA-2024:7004 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2024:6997 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.2) | Fixed | RHSA-2024:7004 |
| Red Hat Enterprise Linux CRB (v. 9) | Fixed | RHSA-2024:6997 |
| Red Hat Enterprise Linux NFV (v. 9) | Fixed | RHSA-2024:6997 |
| Red Hat Enterprise Linux RT (v. 9) | Fixed | RHSA-2024:6997 |
| Red Hat Enterprise Linux Real Time EUS (v.9.2) | Fixed | RHSA-2024:7005 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) | Fixed | RHSA-2024:7005 |
Not affected: 1 product
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2024-36899
- 2026-11-05 Affected versions changed · Red Hat
References
Patch 3
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Sources
- CVE-2024-36899 · CVE Program
- CVE-2024-36899 · NVD
- FIRST EPSS
- CVE-2024-36899 · Red Hat security data · CC BY 4.0
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