In the Linux kernel, the following vulnerability has been resolved: mm/secretmem: fix GUP-fast succeeding on secretmem folios folio_is_secretmem() currently relies on secretmem folios being LRU folios, to save some cycles. However, folios might reside in a folio batch without the LRU flag set, or temporarily have their LRU flag cleared. Consequently, the LRU flag is unreliable for this purpose. In particular, this is the case when secretmem_fault() allocates a fresh page and calls filemap_add_folio()->folio_add_lru(). The folio might be added to the per-cpu folio batch and won't get the LRU flag set until the batch was drained using e.g., lru_add_drain(). Consequently, folio_is_secretmem() might not detect secretmem folios and GUP-fast can succeed in grabbing a secretmem folio, crashing the kernel when we would later try reading/writing to the folio, because the folio has been unmapped from the directmap. Fix it by removing that unreliable check.
History

Wed, 13 Nov 2024 02:30:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-05-19T08:34:30.096Z

Updated: 2024-11-05T09:24:13.973Z

Reserved: 2024-05-17T13:50:33.108Z

Link: CVE-2024-35872

cve-icon Vulnrichment

Updated: 2024-08-02T03:21:48.571Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-05-19T09:15:08.600

Modified: 2024-05-20T13:00:04.957

Link: CVE-2024-35872

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-05-19T00:00:00Z

Links: CVE-2024-35872 - Bugzilla