CVE-2026-23375

MEDIUM EPSS 2.0%
Published Mar 25, 20263mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Mar 25, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: mm: thp: deny THP for files on anonymous inodes file_thp_enabled() incorrectly allows THP for files on anonymous inodes (e.g. guest_memfd and secretmem). These files are created via alloc_file_pseudo(), which does not call get_write_access() and leaves inode->i_writecount at 0. Combined with S_ISREG(inode->i_mode) being true, they appear as read-only regular files when CONFIG_READ_ONLY_THP_FOR_FS is enabled, making them eligible for THP collapse. Anonymous inodes can never pass the inode_is_open_for_write() check since their i_writecount is never incremented through the normal VFS open path. The right thing to do is to exclude them from THP eligibility altogether, since CONFIG_READ_ONLY_THP_FOR_FS was designed for real filesystem files (e.g. shared libraries), not for pseudo-filesystem inodes. For guest_memfd, this allows khugepaged and MADV_COLLAPSE to create large folios in the page cache via the collapse path, but the guest_memfd fault handler does not support large folios. This triggers WARN_ON_ONCE(folio_test_large(folio)) in kvm_gmem_fault_user_mapping(). For secretmem, collapse_file() tries to copy page contents through the direct map, but secretmem pages are removed from the direct map. This can result in a kernel crash: BUG: unable to handle page fault for address: ffff88810284d000 RIP: 0010:memcpy_orig+0x16/0x130 Call Trace: collapse_file hpage_collapse_scan_file madvise_collapse Secretmem is not affected by the crash on upstream as the memory failure recovery handles the failed copy gracefully, but it still triggers confusing false memory failure reports: Memory failure: 0x106d96f: recovery action for clean unevictable LRU page: Recovered Check IS_ANON_FILE(inode) in file_thp_enabled() to deny THP for all anonymous inode files.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
2.0% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-617

Affected Products 11

VendorProductVersionRange
linuxlinux_kernel*≥6.8.1  –  <6.12.78
linuxlinux_kernel*≥6.13  –  <6.18.17
linuxlinux_kernel*≥6.19  –  <6.19.7
linuxlinux_kernel6.8any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 4

  • git.kernel.org https://git.kernel.org/stable/c/0524ee56af2c9bfbad152a810f1ca95de8ca00d7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/08de46a75f91a6661bc1ce0a93614f4bc313c581
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dd085fe9a8ebfc5d10314c60452db38d2b75e609
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f6fa05f0dddd387417d0c28281ddb951582514d6
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0524ee56af2c9bfbad152a810f1ca95de8ca00d7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/08de46a75f91a6661bc1ce0a93614f4bc313c581
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dd085fe9a8ebfc5d10314c60452db38d2b75e609
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f6fa05f0dddd387417d0c28281ddb951582514d6
    Patch