CVE-2026-89986

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix sleeping allocation in alloc_pages_bulk_weighted_interleave() syzbot reported a sleeping function called from invalid context splat in bucket_table_alloc(). When rhashtable_insert_slow() rehashes the table under rcu_read_lock(), it calls bucket_table_alloc(..., GFP_ATOMIC | __GFP_NOWARN). If the bucket table allocation uses vmalloc, __vmalloc_node_range_noprof() invokes vm_area_alloc_pages() -> alloc_pages_bulk_mempolicy_noprof() with the passed GFP_ATOMIC flags. If the current task has an MPOL_WEIGHTED_INTERLEAVE mempolicy, alloc_pages_bulk_weighted_interleave() is called and currently hardcodes GFP_KERNEL when allocating the temporary weights array, triggering a might_alloc() splat in atomic/RCU contexts. Pass the gfp flags (masked with GFP_RECLAIM_MASK to strip page-allocator zone modifiers like __GFP_HIGHMEM) received by alloc_pages_bulk_weighted_interleave() to kmalloc() instead of hardcoding GFP_KERNEL. Since the weights buffer is immediately initialized in full, kmalloc() is sufficient.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/0ceda28f371df9e0bbdaa29214f71fe8298f23d8
https://git.kernel.org/stable/c/2943f1f4b7f2816177060eb9f551f2e6d8b629ba
https://git.kernel.org/stable/c/540e583b66d6402bf556fde5e53c817a54c1afe5
https://git.kernel.org/stable/c/bcb3d0c867ee40dc48e9c085bf328fbc679b6656

Configurations

No configuration.

History

16 Sep 2026, 15:18

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.8

Information

Published : 2026-09-16 11:17

Updated : 2026-09-16 15:18

NVD link : CVE-2026-89986

Mitre link : CVE-2026-89986

CVE.ORG link : CVE-2026-89986

JSON object : View

Products Affected

No product.

CWE

No CWE.

{"id": "CVE-2026-89986", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "fa3bea4e1f8202d787709b7e3654eb0a99aed758", "lessThan": "bcb3d0c867ee40dc48e9c085bf328fbc679b6656", "versionType": "git"}, {"status": "affected", "version": "fa3bea4e1f8202d787709b7e3654eb0a99aed758", "lessThan": "0ceda28f371df9e0bbdaa29214f71fe8298f23d8", "versionType": "git"}, {"status": "affected", "version": "fa3bea4e1f8202d787709b7e3654eb0a99aed758", "lessThan": "2943f1f4b7f2816177060eb9f551f2e6d8b629ba", "versionType": "git"}, {"status": "affected", "version": "fa3bea4e1f8202d787709b7e3654eb0a99aed758", "lessThan": "540e583b66d6402bf556fde5e53c817a54c1afe5", "versionType": "git"}], "programFiles": ["mm/mempolicy.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"status": "unaffected", "version": "0", "lessThan": "6.9", "versionType": "semver"}, {"status": "unaffected", "version": "6.12.110", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.51", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.2.5", "versionType": "semver", "lessThanOrEqual": "7.2.*"}, {"status": "unaffected", "version": "7.3-rc2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["mm/mempolicy.c"], "defaultStatus": "affected"}]}], "published": "2026-09-16T11:17:09.653", "references": [{"url": "https://git.kernel.org/stable/c/0ceda28f371df9e0bbdaa29214f71fe8298f23d8", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/2943f1f4b7f2816177060eb9f551f2e6d8b629ba", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/540e583b66d6402bf556fde5e53c817a54c1afe5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/bcb3d0c867ee40dc48e9c085bf328fbc679b6656", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Received", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/mempolicy: fix sleeping allocation in alloc_pages_bulk_weighted_interleave()\n\nsyzbot reported a sleeping function called from invalid context splat in\nbucket_table_alloc().\n\nWhen rhashtable_insert_slow() rehashes the table under rcu_read_lock(), it\ncalls bucket_table_alloc(..., GFP_ATOMIC | __GFP_NOWARN). If the bucket\ntable allocation uses vmalloc, __vmalloc_node_range_noprof() invokes\nvm_area_alloc_pages() -> alloc_pages_bulk_mempolicy_noprof() with the\npassed GFP_ATOMIC flags.\n\nIf the current task has an MPOL_WEIGHTED_INTERLEAVE mempolicy,\nalloc_pages_bulk_weighted_interleave() is called and currently hardcodes\nGFP_KERNEL when allocating the temporary weights array, triggering a\nmight_alloc() splat in atomic/RCU contexts.\n\nPass the gfp flags (masked with GFP_RECLAIM_MASK to strip page-allocator\nzone modifiers like __GFP_HIGHMEM) received by\nalloc_pages_bulk_weighted_interleave() to kmalloc() instead of hardcoding\nGFP_KERNEL. Since the weights buffer is immediately initialized in full,\nkmalloc() is sufficient."}], "lastModified": "2026-09-16T15:18:22.557", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}