CVE intelligence and bounded remediation
CVE-2024-36899 — Linux Linux Kernel security vulnerability
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) <-- us…
- Severity
- High
- CVSS
- 7 (3.1)
- Published
- 2024-05-30
- CISA KEV
- Not currently listed
- Ecosystem
- linux/kernel
- Weaknesses
- CWE-362, CWE-416
Affected products
- linux / linux_kernel
- linux / linux_kernel / 6.9
Matched remediation archetype
Use-after-free, double free, and expired resource use
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace ownership, references, callbacks, asynchronous tasks, and teardown paths around the affected object or resource.
- Identify reachable inputs and timing or state transitions that can release the object while references remain.
- Confirm affected builds, allocators, feature flags, architectures, and process privileges.
Remediate safely
- Apply the maintained ownership or lifetime fix and rebuild all artifacts containing the affected native code.
- Use explicit ownership, safe reference management, cancellation and join semantics, and idempotent teardown.
- Add deterministic lifetime tests plus isolated sanitizer and concurrency coverage for shutdown and error paths.
Authoritative sources
Complete CVE record and remediation plan
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