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.
Metrics
Affected Vendors & Products
References
History
Tue, 24 Sep 2024 11:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
First Time appeared |
Redhat enterprise Linux
|
|
CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/a:redhat:rhel_eus:9.2 cpe:/o:redhat:enterprise_linux:9 |
|
Vendors & Products |
Redhat enterprise Linux
|
Tue, 24 Sep 2024 06:30:00 +0000
Type | Values Removed | Values Added |
---|---|---|
First Time appeared |
Redhat
Redhat rhel Eus |
|
CPEs | cpe:/a:redhat:rhel_eus:9.2::nfv | |
Vendors & Products |
Redhat
Redhat rhel Eus |
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-05-30T15:29:02.591Z
Updated: 2024-11-05T09:27:43.825Z
Reserved: 2024-05-30T15:25:07.066Z
Link: CVE-2024-36899
Vulnrichment
Updated: 2024-08-02T03:43:50.054Z
NVD
Status : Awaiting Analysis
Published: 2024-05-30T16:15:13.510
Modified: 2024-05-30T18:18:58.870
Link: CVE-2024-36899
Redhat