CVE-2024-49872: mm/gup: fix memfd_pin_folios alloc race panic

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-10-21 · updated 2026-06-17
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: mm/gup: fix memfd_pin_folios alloc race panic If memfd_pin_folios tries to create a hugetlb page, but someone else already did, then folio gets the value -EEXIST here: folio = memfd_alloc_folio(memfd, start_idx); if (IS_ERR(folio)) { ret = PTR_ERR(folio); if (ret != -EEXIST) goto err; then on the next trip through the "while start_idx" loop we panic here: if (folio) { folio_put(folio); To fix, set the folio to NULL on error.

Affected products

Linux kernel: from 6.11 before 6.11.3 — fixed in 6.11.3

How to fix

Upgrade to a fixed version: Linux kernel 6.11.3. Check the vendor advisory for mitigations.

References

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