CVE-2025-39878

In the Linux kernel, the following vulnerability has been resolved: ceph: fix crash after fscrypt_encrypt_pagecache_blocks() error The function move_dirty_folio_in_page_array() was created by commit ce80b76dd327 ("ceph: introduce ceph_process_folio_batch() method") by moving code from ceph_writepages_start() to this function. This new function is supposed to return an error code which is checked by the caller (now ceph_process_folio_batch()), and on error, the caller invokes redirty_page_for_writepage() and then breaks from the loop. However, the refactoring commit has gone wrong, and it by accident, it always returns 0 (= success) because it first NULLs the pointer and then returns PTR_ERR(NULL) which is always 0. This means errors are silently ignored, leaving NULL entries in the page array, which may later crash the kernel. The simple solution is to call PTR_ERR() before clearing the pointer.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/249e0a47cdb46bb9eae65511c569044bd8698d7d	Patch
https://git.kernel.org/stable/c/dd1616ecbea920d228c56729461ed223cc501425	Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:6.17:rc1::::::
	cpe:2.3:o:linux:linux_kernel:6.17:rc2::::::
	cpe:2.3:o:linux:linux_kernel:6.17:rc3::::::
	cpe:2.3:o:linux:linux_kernel:6.17:rc4::::::
	cpe:2.3:o:linux:linux_kernel:6.17:rc5::::::

History

No history.

Information

Published : 2025-09-23 06:15

Updated : 2026-01-14 20:16

NVD link : CVE-2025-39878

Mitre link : CVE-2025-39878

CVE.ORG link : CVE-2025-39878

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-476

NULL Pointer Dereference

{"id": "CVE-2025-39878", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2025-09-23T06:15:47.377", "references": [{"url": "https://git.kernel.org/stable/c/249e0a47cdb46bb9eae65511c569044bd8698d7d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dd1616ecbea920d228c56729461ed223cc501425", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix crash after fscrypt_encrypt_pagecache_blocks() error\n\nThe function move_dirty_folio_in_page_array() was created by commit\nce80b76dd327 (\"ceph: introduce ceph_process_folio_batch() method\") by\nmoving code from ceph_writepages_start() to this function.\n\nThis new function is supposed to return an error code which is checked\nby the caller (now ceph_process_folio_batch()), and on error, the\ncaller invokes redirty_page_for_writepage() and then breaks from the\nloop.\n\nHowever, the refactoring commit has gone wrong, and it by accident, it\nalways returns 0 (= success) because it first NULLs the pointer and\nthen returns PTR_ERR(NULL) which is always 0. This means errors are\nsilently ignored, leaving NULL entries in the page array, which may\nlater crash the kernel.\n\nThe simple solution is to call PTR_ERR() before clearing the pointer."}], "lastModified": "2026-01-14T20:16:10.283", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4CDBA6F5-ADD5-4E49-89EE-9FA2364F2685", "versionEndExcluding": "6.16.8", "versionStartIncluding": "6.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C730CD9A-D969-4A8E-9522-162AAF7C0EE9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "39982C4B-716E-4B2F-8196-FA301F47807D"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "340BEEA9-D70D-4290-B502-FBB1032353B1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "47E4C5C0-079F-4838-971B-8C503D48FCC2"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}