CVE-2022-50446 ARC: mm: fix leakage of memory allocated for PTE
A memory leak in the Linux kernel ARC architecture allows attackers to exhaust system memory, causing 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-2022-50446?
CVE-2022-50446 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 Oct 2025. 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:
ARC: mm: fix leakage of memory allocated for PTE
Since commit d9820ff ("ARC: mm: switch pgtable_t back to struct page *") a memory leakage problem occurs. Memory allocated for page table entries not released during process termination. This issue can be reproduced by a small program that allocates a large amount of memory. After several runs, you'll see that the amount of free memory has reduced and will continue to reduce after each run. All ARC CPUs are effected by this issue. The issue was introduced since the kernel stable release v5.15-rc1.
As described in commit d9820ff after switch pgtable_t back to struct page *, a pointer to "struct page" and appropriate functions are used to allocate and free a memory page for PTEs, but the pmd_pgtable macro hasn't changed and returns the direct virtual address from the PMD (PGD) entry. Than this address used as a parameter in the __pte_free() and as a result this function couldn't release memory page allocated for PTEs.
Fix this issue by changing the pmd_pgtable macro and returning pointer to struct page.
Weakness: CWE-401
Which versions are affected by CVE-2022-50446?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50446?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-50446 being exploited?
There is no known exploitation of CVE-2022-50446 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50446, GHSA-wpvw-hhw9-p3qj, UBUNTU-CVE-2022-50446.