CVE-2021-47368 enetc: Fix illegal access when reading affinity_hint
A use-after-free bug in the enetc driver causes a kernel crash when reading affinity hints, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-47368?
CVE-2021-47368 is a high-severity vulnerability in Linux kernel, published on 21 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:
enetc: Fix illegal access when reading affinity_hint
irq_set_affinity_hit() stores a reference to the cpumask_t parameter in the irq descriptor, and that reference can be accessed later from irq_affinity_hint_proc_show(). Since the cpu_mask parameter passed to irq_set_affinity_hit() has only temporary storage (it's on the stack memory), later accesses to it are illegal. Thus reads from the corresponding procfs affinity_hint file can result in paging request oops.
The issue is fixed by the get_cpu_mask() helper, which provides a permanent storage for the cpumask_t parameter.
Weakness: CWE-400
Which versions are affected by CVE-2021-47368?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47368?
Apply the vendor's patch.
Is CVE-2021-47368 being exploited?
There is no known exploitation of CVE-2021-47368 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47368, GHSA-7hrf-mgqx-vhg4, UBUNTU-CVE-2021-47368.