CVE-2022-49995

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2022-49995", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-06-18T10:57:27.387Z", "datePublished": "2025-06-18T11:00:55.352Z", "dateUpdated": "2026-08-05T08:57:04.391Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:57:04.391Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwriteback: avoid use-after-free after removing device\n\nWhen a disk is removed, bdi_unregister gets called to stop further\nwriteback and wait for associated delayed work to complete. However,\nwb_inode_writeback_end() may schedule bandwidth estimation dwork after\nthis has completed, which can result in the timer attempting to access the\njust freed bdi_writeback.\n\nFix this by checking if the bdi_writeback is alive, similar to when\nscheduling writeback work.\n\nSince this requires wb->work_lock, and wb_inode_writeback_end() may get\ncalled from interrupt, switch wb->work_lock to an irqsafe lock."}], "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 bug is reached via local filesystem writeback and block-device teardown (USB/removable media, del_gendisk \u2192 bdi_unregister), not by processing remote network packets. An attacker needs local access to dirty pages on an affected device.\nAC:L - The attacker can drive both sides of the race by generating writeback I/O and then removing or ejecting the device (e.g. udisks power-off or surprise unplug), and the delayed bw_dwork (~200ms) widens the window; this UAF was hit in practice (KASAN).\nPR:L - An unprivileged user can write to auto-mounted removable storage and trigger or cause its removal without CAP_SYS_ADMIN in the init namespace. Root-only sysfs delete is not required for the worst reasonable removable-media scenario.\nUI:N - The attacker can complete the full sequence (dirty data then eject/remove the device they wrote to) without relying on a separate victim action.\nS:U - This is a host-kernel use-after-free leading to privilege escalation within the same OS security authority, not a VM escape or IOMMU/cross-boundary breakout.\nC:H - Use-after-free of the bdi_writeback object lets an attacker reclaim and control freed kernel memory, enabling arbitrary kernel read primitives.\nI:H - The same UAF is exploitable via heap spray for arbitrary kernel writes and control-flow hijacking through the delayed bandwidth-update work path.\nA:H - The freed bdi_writeback is accessed from delayed work (observed as a KASAN splat), which can oops/panic the kernel even when not fully exploited."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fs-writeback.c", "mm/backing-dev.c", "mm/page-writeback.c"], "versions": [{"version": "45a2966fd64147518dc5bca25f447bd0fb5359ac", "lessThan": "f96b9f7c1676923bce871e728bb49c0dfa5013cc", "status": "affected", "versionType": "git"}, {"version": "45a2966fd64147518dc5bca25f447bd0fb5359ac", "lessThan": "9a6c710f3bc10bc9cc23e1c080b53245b7f9d5b7", "status": "affected", "versionType": "git"}, {"version": "45a2966fd64147518dc5bca25f447bd0fb5359ac", "lessThan": "f87904c075515f3e1d8f4a7115869d3b914674fd", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fs-writeback.c", "mm/backing-dev.c", "mm/page-writeback.c"], "versions": [{"version": "5.15", "status": "affected"}, {"version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.64", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.19.6", "lessThanOrEqual": "5.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.0", "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": "5.15", "versionEndExcluding": "5.15.64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "5.19.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/f96b9f7c1676923bce871e728bb49c0dfa5013cc"}, {"url": "https://git.kernel.org/stable/c/9a6c710f3bc10bc9cc23e1c080b53245b7f9d5b7"}, {"url": "https://git.kernel.org/stable/c/f87904c075515f3e1d8f4a7115869d3b914674fd"}], "title": "writeback: avoid use-after-free after removing device", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/fs-writeback.c", "mm/backing-dev.c", "mm/page-writeback.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "f96b9f7c1676923bce871e728bb49c0dfa5013cc", "status": "affected", "version": "45a2966fd64147518dc5bca25f447bd0fb5359ac", "versionType": "git"}, {"lessThan": "9a6c710f3bc10bc9cc23e1c080b53245b7f9d5b7", "status": "affected", "version": "45a2966fd64147518dc5bca25f447bd0fb5359ac", "versionType": "git"}, {"lessThan": "f87904c075515f3e1d8f4a7115869d3b914674fd", "status": "affected", "version": "45a2966fd64147518dc5bca25f447bd0fb5359ac", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/fs-writeback.c", "mm/backing-dev.c", "mm/page-writeback.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"lessThan": "5.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.64", "versionType": "semver"}, {"lessThanOrEqual": "5.19.*", "status": "unaffected", "version": "5.19.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.0", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "7D84F1BC-C9DF-4483-81B0-7377D6BFAEE6", "versionEndExcluding": "5.15.64", "versionStartIncluding": "5.15", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "89E99903-E16D-475D-954B-2BAC46C98262", "versionEndExcluding": "5.19.6", "versionStartIncluding": "5.16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "E8BD11A3-8643-49B6-BADE-5029A0117325", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "5F0AD220-F6A9-4012-8636-155F1B841FAD", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwriteback: avoid use-after-free after removing device\n\nWhen a disk is removed, bdi_unregister gets called to stop further\nwriteback and wait for associated delayed work to complete. However,\nwb_inode_writeback_end() may schedule bandwidth estimation dwork after\nthis has completed, which can result in the timer attempting to access the\njust freed bdi_writeback.\n\nFix this by checking if the bdi_writeback is alive, similar to when\nscheduling writeback work.\n\nSince this requires wb->work_lock, and wb_inode_writeback_end() may get\ncalled from interrupt, switch wb->work_lock to an irqsafe lock."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: writeback: evitar el Use-After-Free tras retirar un dispositivo. Al retirar un disco, se llama a bdi_unregister para detener la escritura diferida y esperar a que se complete el trabajo retrasado asociado. Sin embargo, wb_inode_writeback_end() puede programar la estimaci\u00f3n de ancho de banda dwork despu\u00e9s de que esto se haya completado, lo que puede provocar que el temporizador intente acceder al bdi_writeback reci\u00e9n liberado. Para solucionar esto, verifique si bdi_writeback est\u00e1 activo, de forma similar a cuando se programa la escritura diferida. Dado que esto requiere wb->work_lock y wb_inode_writeback_end() puede ser llamado desde una interrupci\u00f3n, cambie wb->work_lock a un bloqueo irqsafe."}], "id": "CVE-2022-49995", "lastModified": "2026-08-04T10:18:02.403", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2025-06-18T11:15:27.227", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9a6c710f3bc10bc9cc23e1c080b53245b7f9d5b7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/f87904c075515f3e1d8f4a7115869d3b914674fd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/f96b9f7c1676923bce871e728bb49c0dfa5013cc"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: writeback: avoid use-after-free after removing device", "id": "2373560", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2373560"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nwriteback: avoid use-after-free after removing device\nWhen a disk is removed, bdi_unregister gets called to stop further\nwriteback and wait for associated delayed work to complete. However,\nwb_inode_writeback_end() may schedule bandwidth estimation dwork after\nthis has completed, which can result in the timer attempting to access the\njust freed bdi_writeback.\nFix this by checking if the bdi_writeback is alive, similar to when\nscheduling writeback work.\nSince this requires wb->work_lock, and wb_inode_writeback_end() may get\ncalled from interrupt, switch wb->work_lock to an irqsafe lock."], "name": "CVE-2022-49995", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-06-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2022-49995\nhttps://nvd.nist.gov/vuln/detail/CVE-2022-49995\nhttps://lore.kernel.org/linux-cve-announce/2025061826-CVE-2022-49995-2d74@gregkh/T"], "threat_severity": "Moderate"}

{"created": "2025-06-20T13:55:53.780916+00:00", "updated": "2025-06-20T13:55:53.780945+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}