CVE-2021-47081

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Then cb is used by cb->id later,\nwhich is a potential uaf.\n\nMy patch add a variable 'id' to accept the value of cb->id before the\nhl_cb_put(cb) is called, to avoid the potential uaf."}], "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 by opening and closing the local HabanaLabs char device (/dev/hl*), which triggers context release, memory scrubbing, and gaudi_memset_device_memory; it is not reachable via network packets.\nAC:L - An attacker who can open the device reliably drives the put-then-use-id cleanup on every scrub/memset invocation, and use-after-free races of this kind are treated as attacker-influencible rather than requiring uncontrollable conditions.\nPR:L - hl_device_open performs no capability check, and Gaudi device nodes are routinely granted to unprivileged users via udev group/world permissions in real deployments, matching other scored habanalabs CVEs.\nUI:N - The attacker triggers the bug solely by opening and closing the device themselves; no separate victim action is required.\nS:U - Impact is confined to the host kernel authority (local privilege escalation / memory corruption); there is no VM, IOMMU, or other security-authority boundary crossed.\nC:H - This is a use-after-free on a kernel command-buffer object; UAF enables heap reuse and disclosure of freed object contents, so confidentiality impact is High.\nI:H - Use-after-free of the CB object can be turned into heap spray and arbitrary write / control-flow hijacking primitives, so integrity impact is High.\nA:H - Use-after-free of kernel memory can cause kernel oops/panic or device-driver failure, yielding High availability impact."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/misc/habanalabs/gaudi/gaudi.c"], "versions": [{"version": "423815bf02e257091d5337be5c63b57fc29e4254", "lessThan": "b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7", "status": "affected", "versionType": "git"}, {"version": "423815bf02e257091d5337be5c63b57fc29e4254", "lessThan": "115726c5d312b462c9d9931ea42becdfa838a076", "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/misc/habanalabs/gaudi/gaudi.c"], "versions": [{"version": "5.12", "status": "affected"}, {"version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver"}, {"version": "5.12.7", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.13", "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": "5.12", "versionEndExcluding": "5.12.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.13"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7"}, {"url": "https://git.kernel.org/stable/c/115726c5d312b462c9d9931ea42becdfa838a076"}], "title": "habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-47081", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-03-04T19:32:29.244809Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:14:15.058Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.774Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/115726c5d312b462c9d9931ea42becdfa838a076", "tags": ["x_transferred"]}]}]}}

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One ref of cb is dropped by hl_cb_put(cb) and could be freed\nif other thread also drops one ref. 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One ref of cb is dropped by hl_cb_put(cb) and could be freed\nif other thread also drops one ref. Then cb is used by cb->id later,\nwhich is a potential uaf.\n\nMy patch add a variable 'id' to accept the value of cb->id before the\nhl_cb_put(cb) is called, to avoid the potential uaf."}, {"lang": "es", "value": "En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: habanalabs/gaudi: Corregir un uso potencial despu\u00e9s de liberar en gaudi_memset_device_memory Nuestro analizador de c\u00f3digo report\u00f3 un uaf. En gaudi_memset_device_memory, cb se obtiene a trav\u00e9s de hl_cb_kernel_create() con 2 refcount. Si hl_cs_allocate_job() falla, la ejecuci\u00f3n se ejecuta en la rama release_cb. hl_cb_put(cb) elimina una referencia de cb y podr\u00eda liberarse si otro hilo tambi\u00e9n elimina una referencia. Luego, cb->id usa cb m\u00e1s tarde, que es un uaf potencial. Mi parche agrega una variable 'id' para aceptar el valor de cb->id antes de llamar a hl_cb_put(cb), para evitar el potencial uaf."}], "id": "CVE-2021-47081", "lastModified": "2026-08-04T10:16:44.503", "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"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-47081", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-03-04T19:32:29.244809Z", "version": "2.0.3"}}]}, "published": "2024-03-01T22:15:47.483", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/115726c5d312b462c9d9931ea42becdfa838a076"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/115726c5d312b462c9d9931ea42becdfa838a076"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory", "id": "2267535", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2267535"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.4", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-416", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nhabanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory\nOur code analyzer reported a uaf.\nIn gaudi_memset_device_memory, cb is get via hl_cb_kernel_create()\nwith 2 refcount.\nIf hl_cs_allocate_job() failed, the execution runs into release_cb\nbranch. One ref of cb is dropped by hl_cb_put(cb) and could be freed\nif other thread also drops one ref. Then cb is used by cb->id later,\nwhich is a potential uaf.\nMy patch add a variable 'id' to accept the value of cb->id before the\nhl_cb_put(cb) is called, to avoid the potential uaf.", "A use-after-free vulnerability was found in the Linux kernel, which affects the gaudi component and is caused by a reference attempt cb->id, which may have been previously freed during a call to the hl_cb_put() function."], "name": "CVE-2021-47081", "package_state": [{"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": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-03-01T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47081\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47081\nhttps://lore.kernel.org/linux-cve-announce/2024030143-CVE-2021-47081-e590@gregkh/T/#u"], "statement": "Red Hat Enterprise Linux 8 and 9 are not affected by this vulnerability.", "threat_severity": "Moderate"}

{}