CVE-2021-46971 - OpenCVE

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix unconditional security_locked_down() call Currently, the lockdown state is queried unconditionally, even though its result is used only if the PERF_SAMPLE_REGS_INTR bit is set in attr.sample_type. While that doesn't matter in case of the Lockdown LSM, it causes trouble with the SELinux's lockdown hook implementation. SELinux implements the locked_down hook with a check whether the current task's type has the corresponding "lockdown" class permission ("integrity" or "confidentiality") allowed in the policy. This means that calling the hook when the access control decision would be ignored generates a bogus permission check and audit record. Fix this by checking sample_type first and only calling the hook when its result would be honored.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

No data.

No data.

No data.

References

Link	Providers
https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b
https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce
https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff
https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1
https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e
https://lore.kernel.org/linux-cve-announce/2024022721-CVE-2021-46971-9534@gregkh/T/#u
https://nvd.nist.gov/vuln/detail/CVE-2021-46971
https://www.cve.org/CVERecord?id=CVE-2021-46971

History

Mon, 04 Nov 2024 12:15:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-02-27T18:47:06.674Z

Updated: 2024-11-04T11:56:54.535Z

Reserved: 2024-02-27T18:42:55.943Z

Link: CVE-2021-46971

Vulnrichment

Updated: 2024-08-04T05:17:42.943Z

NVD

Status : Awaiting Analysis

Published: 2024-02-27T19:04:07.343

Modified: 2024-02-28T14:06:45.783

Link: CVE-2021-46971

Redhat

Severity : Low

Publid Date: 2024-02-27T00:00:00Z

Links: CVE-2021-46971 - Bugzilla

{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-46971", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-27T18:42:55.943Z", "datePublished": "2024-02-27T18:47:06.674Z", "dateUpdated": "2024-11-04T11:56:54.535Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-04T11:56:54.535Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix unconditional security_locked_down() call\n\nCurrently, the lockdown state is queried unconditionally, even though\nits result is used only if the PERF_SAMPLE_REGS_INTR bit is set in\nattr.sample_type. While that doesn't matter in case of the Lockdown LSM,\nit causes trouble with the SELinux's lockdown hook implementation.\n\nSELinux implements the locked_down hook with a check whether the current\ntask's type has the corresponding \"lockdown\" class permission\n(\"integrity\" or \"confidentiality\") allowed in the policy. This means\nthat calling the hook when the access control decision would be ignored\ngenerates a bogus permission check and audit record.\n\nFix this by checking sample_type first and only calling the hook when\nits result would be honored."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/events/core.c"], "versions": [{"version": "b0c8fdc7fdb7", "lessThan": "b246759284d6", "status": "affected", "versionType": "git"}, {"version": "b0c8fdc7fdb7", "lessThan": "4348d3b5027b", "status": "affected", "versionType": "git"}, {"version": "b0c8fdc7fdb7", "lessThan": "f5809ca4c311", "status": "affected", "versionType": "git"}, {"version": "b0c8fdc7fdb7", "lessThan": "c7b0208ee370", "status": "affected", "versionType": "git"}, {"version": "b0c8fdc7fdb7", "lessThan": "08ef1af4de5f", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/events/core.c"], "versions": [{"version": "5.4", "status": "affected"}, {"version": "0", "lessThan": "5.4", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.117", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.35", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.11.19", "lessThanOrEqual": "5.11.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.12.2", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.13", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "references": [{"url": "https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff"}, {"url": "https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce"}, {"url": "https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e"}, {"url": "https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1"}, {"url": "https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b"}], "title": "perf/core: Fix unconditional security_locked_down() call", "x_generator": {"engine": "bippy-9e1c9544281a"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-46971", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-02-28T20:22:11.491385Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:13:04.676Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:42.943Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b", "tags": ["x_transferred"]}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:42.943Z"}}, {"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-46971", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-02-28T20:22:11.491385Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-05-23T19:01:13.781Z"}, "title": "CISA ADP Vulnrichment"}], "cna": {"title": "perf/core: Fix unconditional security_locked_down() call", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "b0c8fdc7fdb7", "lessThan": "b246759284d6", "versionType": "git"}, {"status": "affected", "version": "b0c8fdc7fdb7", "lessThan": "4348d3b5027b", "versionType": "git"}, {"status": "affected", "version": "b0c8fdc7fdb7", "lessThan": "f5809ca4c311", "versionType": "git"}, {"status": "affected", "version": "b0c8fdc7fdb7", "lessThan": "c7b0208ee370", "versionType": "git"}, {"status": "affected", "version": "b0c8fdc7fdb7", "lessThan": "08ef1af4de5f", "versionType": "git"}], "programFiles": ["kernel/events/core.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.4"}, {"status": "unaffected", "version": "0", "lessThan": "5.4", "versionType": "semver"}, {"status": "unaffected", "version": "5.4.117", "versionType": "semver", "lessThanOrEqual": "5.4.*"}, {"status": "unaffected", "version": "5.10.35", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.11.19", "versionType": "semver", "lessThanOrEqual": "5.11.*"}, {"status": "unaffected", "version": "5.12.2", "versionType": "semver", "lessThanOrEqual": "5.12.*"}, {"status": "unaffected", "version": "5.13", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["kernel/events/core.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff"}, {"url": "https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce"}, {"url": "https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e"}, {"url": "https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1"}, {"url": "https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b"}], "x_generator": {"engine": "bippy-9e1c9544281a"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix unconditional security_locked_down() call\n\nCurrently, the lockdown state is queried unconditionally, even though\nits result is used only if the PERF_SAMPLE_REGS_INTR bit is set in\nattr.sample_type. While that doesn't matter in case of the Lockdown LSM,\nit causes trouble with the SELinux's lockdown hook implementation.\n\nSELinux implements the locked_down hook with a check whether the current\ntask's type has the corresponding \"lockdown\" class permission\n(\"integrity\" or \"confidentiality\") allowed in the policy. This means\nthat calling the hook when the access control decision would be ignored\ngenerates a bogus permission check and audit record.\n\nFix this by checking sample_type first and only calling the hook when\nits result would be honored."}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-04T11:56:54.535Z"}}}, "cveMetadata": {"cveId": "CVE-2021-46971", "state": "PUBLISHED", "dateUpdated": "2024-11-04T11:56:54.535Z", "dateReserved": "2024-02-27T18:42:55.943Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-02-27T18:47:06.674Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix unconditional security_locked_down() call\n\nCurrently, the lockdown state is queried unconditionally, even though\nits result is used only if the PERF_SAMPLE_REGS_INTR bit is set in\nattr.sample_type. While that doesn't matter in case of the Lockdown LSM,\nit causes trouble with the SELinux's lockdown hook implementation.\n\nSELinux implements the locked_down hook with a check whether the current\ntask's type has the corresponding \"lockdown\" class permission\n(\"integrity\" or \"confidentiality\") allowed in the policy. This means\nthat calling the hook when the access control decision would be ignored\ngenerates a bogus permission check and audit record.\n\nFix this by checking sample_type first and only calling the hook when\nits result would be honored."}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: perf/core: corrige la llamada incondicional a security_locked_down() Actualmente, el estado de bloqueo se consulta incondicionalmente, aunque su resultado se usa solo si el bit PERF_SAMPLE_REGS_INTR est\u00e1 establecido en attr.sample_type. Si bien eso no importa en el caso del Lockdown LSM, causa problemas con la implementaci\u00f3n del gancho de bloqueo de SELinux. SELinux implementa el gancho lock_down comprobando si el tipo de tarea actual tiene el correspondiente permiso de clase de \"bloqueo\" (\"integridad\" o \"confidencialidad\") permitido en la pol\u00edtica. Esto significa que llamar al enlace cuando se ignorar\u00eda la decisi\u00f3n de control de acceso genera una verificaci\u00f3n de permisos y un registro de auditor\u00eda falsos. Solucione este problema verificando sample_type primero y solo llamando al gancho cuando se respete su resultado."}], "id": "CVE-2021-46971", "lastModified": "2024-02-28T14:06:45.783", "metrics": {}, "published": "2024-02-27T19:04:07.343", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: perf/core: Fix unconditional security_locked_down() call", "id": "2266833", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2266833"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N", "status": "draft"}, "cwe": "CWE-413", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nperf/core: Fix unconditional security_locked_down() call\nCurrently, the lockdown state is queried unconditionally, even though\nits result is used only if the PERF_SAMPLE_REGS_INTR bit is set in\nattr.sample_type. While that doesn't matter in case of the Lockdown LSM,\nit causes trouble with the SELinux's lockdown hook implementation.\nSELinux implements the locked_down hook with a check whether the current\ntask's type has the corresponding \"lockdown\" class permission\n(\"integrity\" or \"confidentiality\") allowed in the policy. This means\nthat calling the hook when the access control decision would be ignored\ngenerates a bogus permission check and audit record.\nFix this by checking sample_type first and only calling the hook when\nits result would be honored."], "name": "CVE-2021-46971", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not 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": "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": "2024-02-27T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-46971\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-46971\nhttps://lore.kernel.org/linux-cve-announce/2024022721-CVE-2021-46971-9534@gregkh/T/#u"], "statement": "No Red Hat Products are affected by this vulnerability.", "threat_severity": "Low", "upstream_fix": "kernel 5.4.117, kernel 5.10.35, kernel 5.11.19, kernel 5.12.2, kernel 5.13"}