Upstream information

CVE-2026-31648 at MITRE

Description

In the Linux kernel, the following vulnerability has been resolved:

mm: filemap: fix nr_pages calculation overflow in filemap_map_pages()

When running stress-ng on my Arm64 machine with v7.0-rc3 kernel, I
encountered some very strange crash issues showing up as "Bad page state":

"
[ 734.496287] BUG: Bad page state in process stress-ng-env pfn:415735fb
[ 734.496427] page: refcount:0 mapcount:1 mapping:0000000000000000 index:0x4cf316 pfn:0x415735fb
[ 734.496434] flags: 0x57fffe000000800(owner_2|node=1|zone=2|lastcpupid=0x3ffff)
[ 734.496439] raw: 057fffe000000800 0000000000000000 dead000000000122 0000000000000000
[ 734.496440] raw: 00000000004cf316 0000000000000000 0000000000000000 0000000000000000
[ 734.496442] page dumped because: nonzero mapcount
"

After analyzing this page's state, it is hard to understand why the
mapcount is not 0 while the refcount is 0, since this page is not where
the issue first occurred. By enabling the CONFIG_DEBUG_VM config, I can
reproduce the crash as well and captured the first warning where the issue
appears:

"
[ 734.469226] page: refcount:33 mapcount:0 mapping:00000000bef2d187 index:0x81a0 pfn:0x415735c0
[ 734.469304] head: order:5 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 734.469315] memcg:ffff000807a8ec00
[ 734.469320] aops:ext4_da_aops ino:100b6f dentry name(?):"stress-ng-mmaptorture-9397-0-2736200540"
[ 734.469335] flags: 0x57fffe400000069(locked|uptodate|lru|head|node=1|zone=2|lastcpupid=0x3ffff)
......
[ 734.469364] page dumped because: VM_WARN_ON_FOLIO((_Generic((page + nr_pages - 1),
const struct page *: (const struct folio *)_compound_head(page + nr_pages - 1), struct page *:
(struct folio *)_compound_head(page + nr_pages - 1))) != folio)
[ 734.469390] ------------[ cut here ]------------
[ 734.469393] WARNING: ./include/linux/rmap.h:351 at folio_add_file_rmap_ptes+0x3b8/0x468,
CPU#90: stress-ng-mlock/9430
[ 734.469551] folio_add_file_rmap_ptes+0x3b8/0x468 (P)
[ 734.469555] set_pte_range+0xd8/0x2f8
[ 734.469566] filemap_map_folio_range+0x190/0x400
[ 734.469579] filemap_map_pages+0x348/0x638
[ 734.469583] do_fault_around+0x140/0x198
......
[ 734.469640] el0t_64_sync+0x184/0x188
"

The code that triggers the warning is: "VM_WARN_ON_FOLIO(page_folio(page +
nr_pages - 1) != folio, folio)", which indicates that set_pte_range()
tried to map beyond the large folio's size.

By adding more debug information, I found that 'nr_pages' had overflowed
in filemap_map_pages(), causing set_pte_range() to establish mappings for
a range exceeding the folio size, potentially corrupting fields of pages
that do not belong to this folio (e.g., page->_mapcount).

After above analysis, I think the possible race is as follows:

CPU 0 CPU 1
filemap_map_pages() ext4_setattr()
//get and lock folio with old inode->i_size
next_uptodate_folio()

.......
//shrink the inode->i_size
i_size_write(inode, attr->ia_size);

//calculate the end_pgoff with the new inode->i_size
file_end = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE) - 1;
end_pgoff = min(end_pgoff, file_end);

......
//nr_pages can be overflowed, cause xas.xa_index > end_pgoff
end = folio_next_index(folio) - 1;
nr_pages = min(end, end_pgoff) - xas.xa_index + 1;

......
//map large folio
filemap_map_folio_range()
......
//truncate folios
truncate_pagecache(inode, inode->i_size);

To fix this issue, move the 'end_pgoff' calculation before
next_uptodate_folio(), so the retrieved folio stays consistent with the
file end to avoid
---truncated---

SUSE information

Overall state of this security issue: New

This issue is currently rated as having important severity.

Note from the SUSE Security Team on the kernel-default package

SUSE will no longer fix all CVEs in the Linux Kernel anymore, but declare some bug classes as won't fix. Please refer to TID 21496 for more details.

No SUSE Bugzilla entries cross referenced.

No SUSE Security Announcements cross referenced.


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Desktop 15 SP7 kernel-source Analysis
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-default Analysis
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Live Patching 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Live Patching 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Micro 5.2 kernel-default Analysis
SUSE Linux Enterprise Micro 5.2 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.2 kernel-source Analysis
SUSE Linux Enterprise Micro 5.2 kernel-source-rt Analysis
SUSE Linux Enterprise Micro 5.3 kernel-default Analysis
SUSE Linux Enterprise Micro 5.3 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.3 kernel-source Analysis
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Analysis
SUSE Linux Enterprise Micro 5.4 kernel-default Analysis
SUSE Linux Enterprise Micro 5.4 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.4 kernel-source Analysis
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Analysis
SUSE Linux Enterprise Micro 5.5 kernel-default Analysis
SUSE Linux Enterprise Micro 5.5 kernel-source Analysis
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP7 kernel-source-rt Analysis
SUSE Linux Enterprise Server 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Server 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Server 16.0 kernel-default Analysis
SUSE Linux Enterprise Server 16.0 kernel-source Analysis
SUSE Linux Enterprise Server 16.1 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-source Analysis
SUSE Linux Enterprise Server for SAP applications 16.0 kernel-default Analysis
SUSE Linux Enterprise Server for SAP applications 16.0 kernel-source Analysis
SUSE Linux Enterprise Server for SAP applications 16.1 kernel-source Analysis
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-default Analysis
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-source Analysis
SUSE Linux Micro 6.0 kernel-default Analysis
SUSE Linux Micro 6.0 kernel-source Analysis
SUSE Linux Micro 6.0 kernel-source-rt Analysis
SUSE Linux Micro 6.1 kernel-default Analysis
SUSE Linux Micro 6.1 kernel-source Analysis
SUSE Linux Micro 6.1 kernel-source-rt Analysis
SUSE Linux Micro 6.2 kernel-default Analysis
SUSE Linux Micro 6.2 kernel-source Analysis
SUSE Real Time Module 15 SP7 kernel-source-rt Analysis
openSUSE Leap 15.6 kernel-default Analysis
openSUSE Leap 15.6 kernel-source Analysis
openSUSE Leap 15.6 kernel-source-azure Analysis
openSUSE Leap 15.6 kernel-source-rt Analysis
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-source Analysis
SUSE Linux Enterprise Live Patching 12 SP5 kernel-default Analysis
SUSE Linux Enterprise Live Patching 12 SP5 kernel-source Analysis
SUSE Linux Enterprise Live Patching 15 SP4 kernel-default Analysis
SUSE Linux Enterprise Live Patching 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Live Patching 15 SP5 kernel-default Analysis
SUSE Linux Enterprise Live Patching 15 SP5 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default Analysis
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source Analysis
SUSE Linux Enterprise Server 12 SP5 kernel-source Analysis
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-default Analysis
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-source Analysis
SUSE Linux Enterprise Server 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP5 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP6 kernel-source-azure Analysis
SUSE Linux Enterprise Server 15 SP6-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP6-LTSS kernel-source Analysis
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source-azure Analysis
SUSE Manager Proxy 4.3 kernel-source Analysis
SUSE Manager Proxy LTS 4.3 kernel-source Analysis
SUSE Manager Retail Branch Server 4.3 kernel-source Analysis
SUSE Manager Retail Branch Server LTS 4.3 kernel-source Analysis
SUSE Manager Server 4.3 kernel-source Analysis
SUSE Manager Server LTS 4.3 kernel-source Analysis
Products past their end of life and not receiving proactive updates anymore.
SUSE CaaS Platform 4.0 kernel-source Analysis
SUSE Enterprise Storage 6 kernel-source Analysis
SUSE Enterprise Storage 7 kernel-source Analysis
SUSE Enterprise Storage 7.1 kernel-source Analysis
SUSE Linux Enterprise Desktop 11 SP4 kernel-source Analysis
SUSE Linux Enterprise Desktop 12 SP4 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP6 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP1 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source-azure Analysis
SUSE Linux Enterprise Micro 5.0 kernel-default Analysis
SUSE Linux Enterprise Micro 5.1 kernel-default Analysis
SUSE Linux Enterprise Micro 5.1 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.1 kernel-source-rt Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure Analysis
SUSE Linux Enterprise Real Time 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP3 kernel-source-rt Analysis
SUSE Linux Enterprise Real Time 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Analysis
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt Analysis
SUSE Linux Enterprise Real Time 15 SP6 kernel-source-rt Analysis
SUSE Linux Enterprise Server 11 SP4 kernel-source Analysis
SUSE Linux Enterprise Server 11 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP4 kernel-source Analysis
SUSE Linux Enterprise Server 12 SP4-ESPOS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP1-BCL kernel-source Analysis
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP2-BCL kernel-source Analysis
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP3-BCL kernel-source Analysis
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source Analysis
SUSE Manager Proxy 4.0 kernel-source Analysis
SUSE Manager Proxy 4.1 kernel-source Analysis
SUSE Manager Proxy 4.2 kernel-source Analysis
SUSE Manager Retail Branch Server 4.0 kernel-source Analysis
SUSE Manager Retail Branch Server 4.1 kernel-source Analysis
SUSE Manager Retail Branch Server 4.2 kernel-source Analysis
SUSE Manager Server 4.0 kernel-source Analysis
SUSE Manager Server 4.1 kernel-source Analysis
SUSE Manager Server 4.2 kernel-source Analysis
SUSE OpenStack Cloud 9 kernel-source Analysis
SUSE OpenStack Cloud Crowbar 9 kernel-source Analysis
SUSE Real Time Module 15 SP3 kernel-source-rt Analysis
SUSE Real Time Module 15 SP4 kernel-source-rt Analysis
SUSE Real Time Module 15 SP5 kernel-source-rt Analysis
SUSE Real Time Module 15 SP6 kernel-source-rt Analysis
openSUSE Leap 15.3 kernel-source Analysis
openSUSE Leap 15.3 kernel-source-rt Analysis
openSUSE Leap 15.4 kernel-source Analysis
openSUSE Leap 15.4 kernel-source-rt Analysis
openSUSE Leap 15.5 kernel-source Analysis
openSUSE Leap 15.5 kernel-source-rt Analysis


SUSE Timeline for this CVE

CVE page created: Fri Apr 24 18:02:51 2026
CVE page last modified: Sat Apr 25 16:46:46 2026