cbcvebase.
CVE-2026-23375
published 2026-03-25

CVE-2026-23375: 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…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.12%
2.0th percentile
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.

Affected

38 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.19.8-1 (forky)linux 6.19.8-1 (forky)
linuxlinux
linuxlinux>= 7fbb5e188248c50f737720825da1864ce42536d1 < 08de46a75f91a6661bc1ce0a93614f4bc313c58108de46a75f91a6661bc1ce0a93614f4bc313c581
linuxlinux>= 7fbb5e188248c50f737720825da1864ce42536d1 < 0524ee56af2c9bfbad152a810f1ca95de8ca00d70524ee56af2c9bfbad152a810f1ca95de8ca00d7
linuxlinux>= 7fbb5e188248c50f737720825da1864ce42536d1 < f6fa05f0dddd387417d0c28281ddb951582514d6f6fa05f0dddd387417d0c28281ddb951582514d6
linuxlinux>= 7fbb5e188248c50f737720825da1864ce42536d1 < dd085fe9a8ebfc5d10314c60452db38d2b75e609dd085fe9a8ebfc5d10314c60452db38d2b75e609
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.19.8-16.19.8-1
linuxlinux_kernel>= 6.13 < 6.18.176.18.17
linuxlinux_kernel>= 6.13.0 < 6.18.176.18.17
linuxlinux_kernel>= 6.19 < 6.19.76.19.7
linuxlinux_kernel>= 6.19.0 < 6.19.76.19.7
linuxlinux_kernel>= 6.8.0 < 6.12.786.12.78
linuxlinux_kernel>= 6.8.1 < 6.12.786.12.78
ubuntulinux
ubuntulinux-aws
ubuntulinux-azure
ubuntulinux-azure-6.8
ubuntulinux-azure-fde
ubuntulinux-azure-fde-6.8
ubuntulinux-azure-fips
ubuntulinux-fips
ubuntulinux-gcp
ubuntulinux-gcp-6.8

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vendor_redhat7.0MEDIUM
vendor_ubuntu2.0LOW
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