CVE-2024-35887 ax25: fix use-after-free bugs caused by ax25_ds_del_timer
A use-after-free vulnerability in the Linux kernel AX.25 subsystem allows attackers to execute arbitrary code or escalate privileges during device detachment.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-35887?
CVE-2024-35887 is a high-severity use after free vulnerability in Linux kernel, published on 19 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ax25: fix use-after-free bugs caused by ax25_ds_del_timer
When the ax25 device is detaching, the ax25_dev_device_down() calls ax25_ds_del_timer() to cleanup the slave_timer. When the timer handler is running, the ax25_ds_del_timer() that calls del_timer() in it will return directly. As a result, the use-after-free bugs could happen, one of the scenarios is shown below:
(Thread 1) | (Thread 2) | ax25_ds_timeout() ax25_dev_device_down() | ax25_ds_del_timer() | del_timer() | ax25_dev_put() //FREE | | ax25_dev-> //USE
In order to mitigate bugs, when the device is detaching, use timer_shutdown_sync() to stop the timer.
Weakness: CWE-416
Which versions are affected by CVE-2024-35887?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-35887?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2024-35887 being exploited?
There is no known exploitation of CVE-2024-35887 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-54730, BELL-CVE-2024-35887, DEBIAN-CVE-2024-35887, GHSA-x3w9-8c2f-ccvj, ROOT-OS-DEBIAN-11-CVE-2024-35887, ROOT-OS-DEBIAN-12-CVE-2024-35887 and 1 more.