CVE - CVE-2024-36899

CVE-ID
CVE-2024-36899	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
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
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/02f6b0e1ec7e0e7d059dddc893645816552039da URL:https://git.kernel.org/stable/c/02f6b0e1ec7e0e7d059dddc893645816552039da MISC:https://git.kernel.org/stable/c/95ca7c90eaf5ea8a8460536535101e3e81160e2a URL:https://git.kernel.org/stable/c/95ca7c90eaf5ea8a8460536535101e3e81160e2a MISC:https://git.kernel.org/stable/c/ca710b5f40b8b16fdcad50bebd47f50e4c62d239 URL:https://git.kernel.org/stable/c/ca710b5f40b8b16fdcad50bebd47f50e4c62d239
Assigning CNA
kernel.org
Date Record Created
20240530	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240530)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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