CVE-2022-50446

MEDIUMCVSS 5.5/10EPSS 0.14%

Last modified

CVE-2022-50446 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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. EPSS estimates a 0.14% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.14%

3.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.15, < 5.15.77
LinuxLinux Kernel>= 5.16, < 6.0.7
LinuxLinux Kernel6.1Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2022-50446?
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.
How severe is CVE-2022-50446?
CVE-2022-50446 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.
How do I fix CVE-2022-50446?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2022-50446?

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Source: NVD / NIST