{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-50421", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-09-17T14:53:07.004Z", "datePublished": "2025-10-01T11:41:54.351Z", "dateUpdated": "2026-08-05T08:58:44.673Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:58:44.673Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrpmsg: char: Avoid double destroy of default endpoint\n\nThe rpmsg_dev_remove() in rpmsg_core is the place for releasing\nthis default endpoint.\n\nSo need to avoid destroying the default endpoint in\nrpmsg_chrdev_eptdev_destroy(), this should be the same as\nrpmsg_eptdev_release(). Otherwise there will be double destroy\nissue that ept->refcount report warning:\n\nrefcount_t: underflow; use-after-free.\n\nCall trace:\n refcount_warn_saturate+0xf8/0x150\n virtio_rpmsg_destroy_ept+0xd4/0xec\n rpmsg_dev_remove+0x60/0x70\n\nThe issue can be reproduced by stopping remoteproc before\nclosing the /dev/rpmsgX." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached only through local rpmsg char device operations (/dev/rpmsgX open plus channel/device teardown via remoteproc stop, NS_DESTROY, or RPMSG_RELEASE_DEV_IOCTL); it is not reachable from network packets or adjacent-link protocols.\nAC:L - With /dev/rpmsgX held open on a default_ept (rpmsg-raw) channel, device removal deterministically double-destroys the same endpoint in rpmsg_chrdev_eptdev_destroy then rpmsg_dev_remove; the attacker who opens the device and triggers teardown fully controls both steps with no race or external precondition.\nPR:L - On the platforms where RPMSG_CHAR is actually deployed (Android/QCOM, automotive, OpenAMP embedded), /dev/rpmsg* is routinely granted to non-root HALs/service users via udev/sepolicy, and those same contexts can drive channel release or remoteproc restart without full init-namespace root.\nUI:N - The attacker opens /dev/rpmsgX and triggers device removal themselves; no separate victim action such as mounting a filesystem or opening a crafted file is required.\nS:U - Impact is a host-kernel heap use-after-free of the rpmsg_endpoint within the same OS security authority, with no VM escape, IOMMU bypass, or other cross-boundary compromise.\nC:H - The first rpmsg_destroy_ept kfree's the default endpoint while rpdev->ept still points at it, so the second destroy is a classic UAF on a reclaimable slab object that per guidance enables arbitrary kernel memory disclosure.\nI:H - The same freed rpmsg_endpoint can be sprayed before the second destroy walks ept->ops/rpdev/refcount, yielding a heap corruption and control-flow hijack primitive consistent with UAF integrity High.\nA:H - The bug manifests as refcount underflow use-after-free (and kernel oops under KASAN); per guidance any UAF scores Availability High even when not fully exploited for code execution." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/rpmsg/rpmsg_char.c" ], "versions": [ { "version": "bea9b79c2d10fecf7bfa26e212ecefe61d232e39", "lessThan": "ef828a39d6a7028836eaf37df3ad568c8c2dd6f9", "status": "affected", "versionType": "git" }, { "version": "bea9b79c2d10fecf7bfa26e212ecefe61d232e39", "lessThan": "3f20ef7a845c2c8d7ec82ecffa20d95cab5ecfeb", "status": "affected", "versionType": "git" }, { "version": "bea9b79c2d10fecf7bfa26e212ecefe61d232e39", "lessThan": "467233a4ac29b215d492843d067a9f091e6bf0c5", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/rpmsg/rpmsg_char.c" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "5.19.17", "lessThanOrEqual": "5.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.0.3", "lessThanOrEqual": "6.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "5.19.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.0.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ef828a39d6a7028836eaf37df3ad568c8c2dd6f9" }, { "url": "https://git.kernel.org/stable/c/3f20ef7a845c2c8d7ec82ecffa20d95cab5ecfeb" }, { "url": "https://git.kernel.org/stable/c/467233a4ac29b215d492843d067a9f091e6bf0c5" } ], "title": "rpmsg: char: Avoid double destroy of default endpoint", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "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" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2022-50421", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-01-14T17:39:44.735824Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-14T17:42:46.316Z" } } ] } }