mm/debug_vm_pgtable: clear page table entries at destroy_args()
In the Linux kernel, the following vulnerability has been resolved: mm/debug_vm_pgtable: clear page table entries at destroy_args() The mm/debug_vm_pagetable test allocates manually page table entries for the tests it runs, using also its manually allocated mm_struct. That in itself is ok, but when it exits, at destroy_args() it fails to clear those entries with the *_clear functions. The problem is that leaves stale entries. If another process allocates an mm_struct with a pgd at the same address, it may end up running into the stale entry. This is happening in practice on a debug kernel with CONFIG_DEBUG_VM_PGTABLE=y, for example this is the output with some extra debugging I added (it prints a warning trace if pgtables_bytes goes negative, in addition to the warning at check_mm() function): [ 2.539353] debug_vm_pgtable: [get_random_vaddr ]: random_vaddr is 0x7ea247140000 [ 2.539366] kmem_cache info [ 2.539374] kmem_cachep 0x000000002ce82385 - freelist 0x0000000000000000 - offset 0x508 [ 2.539447] debug_vm_pgtable: [init_args ]: args->mm is 0x000000002267cc9e (...) [ 2.552800] WARNING: CPU: 5 PID: 116 at include/linux/mm.h:2841 free_pud_range+0x8bc/0x8d0 [ 2.552816] Modules linked in: [ 2.552843] CPU: 5 UID: 0 PID: 116 Comm: modprobe Not tainted 6.12.0-105.debug_vm2.el10.ppc64le+debug #1 VOLUNTARY [ 2.552859] Hardware name: IBM,9009-41A POWER9 (architected) 0x4e0202 0xf000005 of:IBM,FW910.00 (VL910_062) hv:phyp pSeries [ 2.552872] NIP: c0000000007eef3c LR: c0000000007eef30
CVE-2025-39776
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-2025-39776
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": "3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a",
"lessThan": "7bf57a0709cd7c9088cea8de023d6f4fbf2518b0",
"versionType": "git"
},
{
"status": "affected",
"version": "3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a",
"lessThan": "47d2a149611b8a94d24add9868c442a4af278658",
"versionType": "git"
},
{
"status": "affected",
"version": "3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a",
"lessThan": "63962ff932ef359925b94be2a88df6b4fd4fed0a",
"versionType": "git"
},
{
"status": "affected",
"version": "3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a",
"lessThan": "61a9f2e5c49f05e3ea2c16674540a075a1b4be6f",
"versionType": "git"
},
{
"status": "affected",
"version": "3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a",
"lessThan": "561171db3b3eb759ba3f284dba7a76f4476ade03",
"versionType": "git"
},
{
"status": "affected",
"version": "3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a",
"lessThan": "dde30854bddfb5d69f30022b53c5955a41088b33",
"versionType": "git"
}
],
"programFiles": [
"mm/debug_vm_pgtable.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.190",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.149",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.103",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.44",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.16.4",
"versionType": "semver",
"lessThanOrEqual": "6.16.*"
},
{
"status": "unaffected",
"version": "6.17",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"mm/debug_vm_pgtable.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-39776
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30627 · Revision 1
- Added to Heist Feed
- Publisher date