mm: filemap: fix nr_pages calculation overflow in filemap_map_pages()
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
CVE-2026-31648
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-31648
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "fe601b70eac6cd266e8d7d55030e90a73ed0e339",
"lessThan": "88591194df736a508dd5461ab2167a61e98caac1",
"versionType": "git"
},
{
"status": "affected",
"version": "743a2753a02e805347969f6f89f38b736850d808",
"lessThan": "633ab680c405ac390e6bec5b74aaf46197c837b6",
"versionType": "git"
},
{
"status": "affected",
"version": "743a2753a02e805347969f6f89f38b736850d808",
"lessThan": "576543bedd616254032d4ebe54a90076f9e31740",
"versionType": "git"
},
{
"status": "affected",
"version": "743a2753a02e805347969f6f89f38b736850d808",
"lessThan": "9316a820b9aae07d44469d6485376dad824c5b3f",
"versionType": "git"
},
{
"status": "affected",
"version": "743a2753a02e805347969f6f89f38b736850d808",
"lessThan": "f58df566524ebcdfa394329c64f47e3c9257516e",
"versionType": "git"
},
{
"status": "affected",
"version": "84ede15f27c06b111d1398dfa80b6fac4b135e34",
"versionType": "git"
},
{
"status": "affected",
"version": "6.6.117",
"lessThan": "6.6.135",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.159",
"lessThan": "6.2",
"versionType": "semver"
}
],
"programFiles": [
"mm/filemap.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.135",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.82",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.23",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.13",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"mm/filemap.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-31648
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39936 · Revision 1
- Added to Heist Feed
- Publisher date