CVE Vulnerabilities


Use After Free

Published: Feb 23, 2024 | Modified: Apr 17, 2024
CVSS 3.x
CVSS 2.x

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache

There is a potential UAF scenario in the case of an LPI translation cache hit racing with an operation that invalidates the cache, such as a DISCARD ITS command. The root of the problem is that vgic_its_check_cache() does not elevate the refcount on the vgic_irq before dropping the lock that serializes refcount changes.

Have vgic_its_check_cache() raise the refcount on the returned vgic_irq and add the corresponding decrement after queueing the interrupt.


Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

Affected Software

Name Vendor Start Version End Version
Linux_kernel Linux * 5.4.269 (excluding)
Linux_kernel Linux 5.5.0 (including) 5.10.209 (excluding)
Linux_kernel Linux 5.11.0 (including) 5.15.148 (excluding)
Linux_kernel Linux 5.16.0 (including) 6.1.75 (excluding)
Linux_kernel Linux 6.2.0 (including) 6.6.14 (excluding)
Linux_kernel Linux 6.7.0 (including) 6.7.2 (excluding)

Extended Description

The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:

In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Potential Mitigations