CVE-2026-89742

In the Linux kernel, the following vulnerability has been resolved: rapidio: mport_cdev: fix use-after-free in dma_req_free() dma_req_free() acquires buf_mutex through req->map, drops the mapping reference with kref_put(), and then dereferences req->map again to unlock the mutex. If kref_put() drops the last reference, mport_release_mapping() frees the mapping, and the subsequent mutex_unlock() dereferences a freed object. This is a use-after-free. Fix this by caching map and md before kref_put(), clearing req->map while holding buf_mutex, and using the cached md for mutex unlocking. The bug is reachable from userspace via the RapidIO mport character device interface.

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/00c5ed913b0dc563fbeb8a97ea8916c03bbbbf6a
https://git.kernel.org/stable/c/211c68d817a3d9dc14c0026a59da7cac30f8147e
https://git.kernel.org/stable/c/26ccfe7d69e27b0d933ae0a64a23a0cb9b9a85a6
https://git.kernel.org/stable/c/5cbef379a94b161726c5f504598bf4791d45cedc
https://git.kernel.org/stable/c/9a9929ec875ff20922c90c96fd544ae8a2a61a8d
https://git.kernel.org/stable/c/bd8881c24a9520f9c3d3e855d866197f63e471a7
https://git.kernel.org/stable/c/e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0
https://git.kernel.org/stable/c/fc79c07cdcde02c5b17633d78777de6ac2c14b29

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-11 20:20

Updated : 2026-09-14 13:19

NVD link : CVE-2026-89742

Mitre link : CVE-2026-89742

CVE.ORG link : CVE-2026-89742

JSON object : View

Products Affected

No product.

CWE

No CWE.

{"id": "CVE-2026-89742", "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": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "00c5ed913b0dc563fbeb8a97ea8916c03bbbbf6a", "versionType": "git"}, {"status": "affected", "version": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "fc79c07cdcde02c5b17633d78777de6ac2c14b29", "versionType": "git"}, {"status": "affected", "version": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "26ccfe7d69e27b0d933ae0a64a23a0cb9b9a85a6", "versionType": "git"}, {"status": "affected", "version": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "bd8881c24a9520f9c3d3e855d866197f63e471a7", "versionType": "git"}, {"status": "affected", "version": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "9a9929ec875ff20922c90c96fd544ae8a2a61a8d", "versionType": "git"}, {"status": "affected", "version": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0", "versionType": "git"}, {"status": "affected", "version": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "211c68d817a3d9dc14c0026a59da7cac30f8147e", "versionType": "git"}, {"status": "affected", "version": "e8de370188d098bb49483c287b44925957c3c9b6", "lessThan": "5cbef379a94b161726c5f504598bf4791d45cedc", "versionType": "git"}], "programFiles": ["drivers/rapidio/devices/rio_mport_cdev.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.6"}, {"status": "unaffected", "version": "0", "lessThan": "4.6", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.270", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.221", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.188", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.157", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.109", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.50", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.2.4", "versionType": "semver", "lessThanOrEqual": "7.2.*"}, {"status": "unaffected", "version": "7.3-rc1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/rapidio/devices/rio_mport_cdev.c"], "defaultStatus": "affected"}]}], "published": "2026-09-11T20:20:04.863", "references": [{"url": "https://git.kernel.org/stable/c/00c5ed913b0dc563fbeb8a97ea8916c03bbbbf6a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/211c68d817a3d9dc14c0026a59da7cac30f8147e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/26ccfe7d69e27b0d933ae0a64a23a0cb9b9a85a6", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5cbef379a94b161726c5f504598bf4791d45cedc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9a9929ec875ff20922c90c96fd544ae8a2a61a8d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/bd8881c24a9520f9c3d3e855d866197f63e471a7", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/fc79c07cdcde02c5b17633d78777de6ac2c14b29", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Received", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrapidio: mport_cdev: fix use-after-free in dma_req_free()\n\ndma_req_free() acquires buf_mutex through req->map, drops the mapping\nreference with kref_put(), and then dereferences req->map again to unlock\nthe mutex.\n\nIf kref_put() drops the last reference, mport_release_mapping() frees the\nmapping, and the subsequent mutex_unlock() dereferences a freed object. \nThis is a use-after-free.\n\nFix this by caching map and md before kref_put(), clearing req->map while\nholding buf_mutex, and using the cached md for mutex unlocking.\n\nThe bug is reachable from userspace via the RapidIO mport character device\ninterface."}], "lastModified": "2026-09-14T13:19:23.040", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}