{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2024-56640", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-27T15:00:39.839Z", "datePublished": "2024-12-27T15:02:42.253Z", "dateUpdated": "2025-02-11T15:45:22.074Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-01-20T06:24:51.426Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix LGR and link use-after-free issue\n\nWe encountered a LGR/link use-after-free issue, which manifested as\nthe LGR/link refcnt reaching 0 early and entering the clear process,\nmaking resource access unsafe.\n\n refcount_t: addition on 0; use-after-free.\n WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140\n Workqueue: events smc_lgr_terminate_work [smc]\n Call trace:\n refcount_warn_saturate+0x9c/0x140\n __smc_lgr_terminate.part.45+0x2a8/0x370 [smc]\n smc_lgr_terminate_work+0x28/0x30 [smc]\n process_one_work+0x1b8/0x420\n worker_thread+0x158/0x510\n kthread+0x114/0x118\n\nor\n\n refcount_t: underflow; use-after-free.\n WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140\n Workqueue: smc_hs_wq smc_listen_work [smc]\n Call trace:\n refcount_warn_saturate+0xf0/0x140\n smcr_link_put+0x1cc/0x1d8 [smc]\n smc_conn_free+0x110/0x1b0 [smc]\n smc_conn_abort+0x50/0x60 [smc]\n smc_listen_find_device+0x75c/0x790 [smc]\n smc_listen_work+0x368/0x8a0 [smc]\n process_one_work+0x1b8/0x420\n worker_thread+0x158/0x510\n kthread+0x114/0x118\n\nIt is caused by repeated release of LGR/link refcnt. One suspect is that\nsmc_conn_free() is called repeatedly because some smc_conn_free() from\nserver listening path are not protected by sock lock.\n\ne.g.\n\nCalls under socklock | smc_listen_work\n-------------------------------------------------------\nlock_sock(sk) | smc_conn_abort\nsmc_conn_free | \\- smc_conn_free\n\\- smcr_link_put | \\- smcr_link_put (duplicated)\nrelease_sock(sk)\n\nSo here add sock lock protection in smc_listen_work() path, making it\nexclusive with other connection operations."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/smc/af_smc.c"], "versions": [{"version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "f502a88fdd415647a1f2dc45fac71b9c522a052b", "status": "affected", "versionType": "git"}, {"version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "0cf598548a6c36d90681d53c6b77d52363f2f295", "status": "affected", "versionType": "git"}, {"version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "673d606683ac70bc074ca6676b938bff18635226", "status": "affected", "versionType": "git"}, {"version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "6f0ae06a234a78ae137064f2c89135ac078a00eb", "status": "affected", "versionType": "git"}, {"version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/smc/af_smc.c"], "versions": [{"version": "4.18", "status": "affected"}, {"version": "0", "lessThan": "4.18", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.174", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.120", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.66", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.5", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.13", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "references": [{"url": "https://git.kernel.org/stable/c/f502a88fdd415647a1f2dc45fac71b9c522a052b"}, {"url": "https://git.kernel.org/stable/c/0cf598548a6c36d90681d53c6b77d52363f2f295"}, {"url": "https://git.kernel.org/stable/c/673d606683ac70bc074ca6676b938bff18635226"}, {"url": "https://git.kernel.org/stable/c/6f0ae06a234a78ae137064f2c89135ac078a00eb"}, {"url": "https://git.kernel.org/stable/c/2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7"}], "title": "net/smc: fix LGR and link use-after-free issue", "x_generator": {"engine": "bippy-5f407fcff5a0"}}, "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-2024-56640", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2025-02-11T15:41:51.231757Z"}}}], "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": "2025-02-11T15:45:22.074Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "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-2024-56640", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2025-02-11T15:41:51.231757Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-11T15:41:52.600Z"}}], "cna": {"title": "net/smc: fix LGR and link use-after-free issue", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "f502a88fdd415647a1f2dc45fac71b9c522a052b", "versionType": "git"}, {"status": "affected", "version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "0cf598548a6c36d90681d53c6b77d52363f2f295", "versionType": "git"}, {"status": "affected", "version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "673d606683ac70bc074ca6676b938bff18635226", "versionType": "git"}, {"status": "affected", "version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "6f0ae06a234a78ae137064f2c89135ac078a00eb", "versionType": "git"}, {"status": "affected", "version": "3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8", "lessThan": "2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7", "versionType": "git"}], "programFiles": ["net/smc/af_smc.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.18"}, {"status": "unaffected", "version": "0", "lessThan": "4.18", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.174", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.120", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.66", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.5", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.13", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/smc/af_smc.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/f502a88fdd415647a1f2dc45fac71b9c522a052b"}, {"url": "https://git.kernel.org/stable/c/0cf598548a6c36d90681d53c6b77d52363f2f295"}, {"url": "https://git.kernel.org/stable/c/673d606683ac70bc074ca6676b938bff18635226"}, {"url": "https://git.kernel.org/stable/c/6f0ae06a234a78ae137064f2c89135ac078a00eb"}, {"url": "https://git.kernel.org/stable/c/2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7"}], "x_generator": {"engine": "bippy-5f407fcff5a0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix LGR and link use-after-free issue\n\nWe encountered a LGR/link use-after-free issue, which manifested as\nthe LGR/link refcnt reaching 0 early and entering the clear process,\nmaking resource access unsafe.\n\n refcount_t: addition on 0; use-after-free.\n WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140\n Workqueue: events smc_lgr_terminate_work [smc]\n Call trace:\n refcount_warn_saturate+0x9c/0x140\n __smc_lgr_terminate.part.45+0x2a8/0x370 [smc]\n smc_lgr_terminate_work+0x28/0x30 [smc]\n process_one_work+0x1b8/0x420\n worker_thread+0x158/0x510\n kthread+0x114/0x118\n\nor\n\n refcount_t: underflow; use-after-free.\n WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140\n Workqueue: smc_hs_wq smc_listen_work [smc]\n Call trace:\n refcount_warn_saturate+0xf0/0x140\n smcr_link_put+0x1cc/0x1d8 [smc]\n smc_conn_free+0x110/0x1b0 [smc]\n smc_conn_abort+0x50/0x60 [smc]\n smc_listen_find_device+0x75c/0x790 [smc]\n smc_listen_work+0x368/0x8a0 [smc]\n process_one_work+0x1b8/0x420\n worker_thread+0x158/0x510\n kthread+0x114/0x118\n\nIt is caused by repeated release of LGR/link refcnt. One suspect is that\nsmc_conn_free() is called repeatedly because some smc_conn_free() from\nserver listening path are not protected by sock lock.\n\ne.g.\n\nCalls under socklock | smc_listen_work\n-------------------------------------------------------\nlock_sock(sk) | smc_conn_abort\nsmc_conn_free | \\- smc_conn_free\n\\- smcr_link_put | \\- smcr_link_put (duplicated)\nrelease_sock(sk)\n\nSo here add sock lock protection in smc_listen_work() path, making it\nexclusive with other connection operations."}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-01-20T06:24:51.426Z"}}}, "cveMetadata": {"cveId": "CVE-2024-56640", "state": "PUBLISHED", "dateUpdated": "2025-02-11T15:45:22.074Z", "dateReserved": "2024-12-27T15:00:39.839Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-12-27T15:02:42.253Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "A8151951-069A-4828-9C8E-5430FD2D7D67", "versionEndExcluding": "5.15.174", "versionStartIncluding": "4.18", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "09AC6122-E2A4-40FE-9D33-268A1B2EC265", "versionEndExcluding": "6.1.120", "versionStartIncluding": "5.16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "29A976AD-B9AB-4A95-9F08-7669F8847EB9", "versionEndExcluding": "6.6.66", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "9501D045-7A94-42CA-8B03-821BE94A65B7", "versionEndExcluding": "6.12.5", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*", "matchCriteriaId": "62567B3C-6CEE-46D0-BC2E-B3717FBF7D13", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix LGR and link use-after-free issue\n\nWe encountered a LGR/link use-after-free issue, which manifested as\nthe LGR/link refcnt reaching 0 early and entering the clear process,\nmaking resource access unsafe.\n\n refcount_t: addition on 0; use-after-free.\n WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140\n Workqueue: events smc_lgr_terminate_work [smc]\n Call trace:\n refcount_warn_saturate+0x9c/0x140\n __smc_lgr_terminate.part.45+0x2a8/0x370 [smc]\n smc_lgr_terminate_work+0x28/0x30 [smc]\n process_one_work+0x1b8/0x420\n worker_thread+0x158/0x510\n kthread+0x114/0x118\n\nor\n\n refcount_t: underflow; use-after-free.\n WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140\n Workqueue: smc_hs_wq smc_listen_work [smc]\n Call trace:\n refcount_warn_saturate+0xf0/0x140\n smcr_link_put+0x1cc/0x1d8 [smc]\n smc_conn_free+0x110/0x1b0 [smc]\n smc_conn_abort+0x50/0x60 [smc]\n smc_listen_find_device+0x75c/0x790 [smc]\n smc_listen_work+0x368/0x8a0 [smc]\n process_one_work+0x1b8/0x420\n worker_thread+0x158/0x510\n kthread+0x114/0x118\n\nIt is caused by repeated release of LGR/link refcnt. One suspect is that\nsmc_conn_free() is called repeatedly because some smc_conn_free() from\nserver listening path are not protected by sock lock.\n\ne.g.\n\nCalls under socklock | smc_listen_work\n-------------------------------------------------------\nlock_sock(sk) | smc_conn_abort\nsmc_conn_free | \\- smc_conn_free\n\\- smcr_link_put | \\- smcr_link_put (duplicated)\nrelease_sock(sk)\n\nSo here add sock lock protection in smc_listen_work() path, making it\nexclusive with other connection operations."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/smc: inicializar close_work antes para evitar advertencias Encontramos una advertencia que indicaba que close_work se cancel\u00f3 antes de la inicializaci\u00f3n. ADVERTENCIA: CPU: 7 PID: 111103 en kernel/workqueue.c:3047 __flush_work+0x19e/0x1b0 Workqueue: eventos smc_lgr_terminate_work [smc] RIP: 0010:__flush_work+0x19e/0x1b0 Rastreo de llamadas: ? __wake_up_common+0x7a/0x190 ? trabajo_ocupado+0x80/0x80 __cancelar_temporizador_trabajo+0xe3/0x160 smc_cerrar_cancelar_trabajo+0x1a/0x70 [smc] smc_cerrar_aborto_activo+0x207/0x360 [smc] __smc_lgr_terminate.part.38+0xc8/0x180 [smc] proceso_uno_trabajo+0x19e/0x340 subproceso_trabajador+0x30/0x370 ? proceso_uno_trabajo+0x340/0x340 kthread+0x117/0x130 ? __kthread_cancel_work+0x50/0x50 ret_from_fork+0x22/0x30 Esto se debe a que cuando se activa smc_close_cancel_work, p. ej., el controlador RDMA es rmmod y se termina el LGR, conn->close_work se vac\u00eda antes de la inicializaci\u00f3n, lo que genera WARN_ON(!work->func). __smc_lgr_terminate | smc_connect_{rdma|ism} ------------------------------------------------------------- | smc_conn_create | \\- smc_lgr_register_conn para conn en lgr->conns_all | \\- smc_conn_kill | \\- smc_close_active_abort | \\- smc_close_cancel_work | \\- cancel_work_sync | \\- __flush_work | (close_work) | | smc_close_init | \\- INIT_WORK(&close_work) Solucione esto inicializando close_work antes de establecer la conexi\u00f3n."}], "id": "CVE-2024-56640", "lastModified": "2025-02-11T16:15:46.470", "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": "nvd@nist.gov", "type": "Primary"}, {"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": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2024-12-27T15:15:23.730", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/0cf598548a6c36d90681d53c6b77d52363f2f295"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/673d606683ac70bc074ca6676b938bff18635226"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/6f0ae06a234a78ae137064f2c89135ac078a00eb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/f502a88fdd415647a1f2dc45fac71b9c522a052b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-416"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: net/smc: fix LGR and link use-after-free issue", "id": "2334532", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2334532"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.4", "cvss3_scoring_vector": "CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-416", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/smc: fix LGR and link use-after-free issue\nWe encountered a LGR/link use-after-free issue, which manifested as\nthe LGR/link refcnt reaching 0 early and entering the clear process,\nmaking resource access unsafe.\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140\nWorkqueue: events smc_lgr_terminate_work [smc]\nCall trace:\nrefcount_warn_saturate+0x9c/0x140\n__smc_lgr_terminate.part.45+0x2a8/0x370 [smc]\nsmc_lgr_terminate_work+0x28/0x30 [smc]\nprocess_one_work+0x1b8/0x420\nworker_thread+0x158/0x510\nkthread+0x114/0x118\nor\nrefcount_t: underflow; use-after-free.\nWARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140\nWorkqueue: smc_hs_wq smc_listen_work [smc]\nCall trace:\nrefcount_warn_saturate+0xf0/0x140\nsmcr_link_put+0x1cc/0x1d8 [smc]\nsmc_conn_free+0x110/0x1b0 [smc]\nsmc_conn_abort+0x50/0x60 [smc]\nsmc_listen_find_device+0x75c/0x790 [smc]\nsmc_listen_work+0x368/0x8a0 [smc]\nprocess_one_work+0x1b8/0x420\nworker_thread+0x158/0x510\nkthread+0x114/0x118\nIt is caused by repeated release of LGR/link refcnt. One suspect is that\nsmc_conn_free() is called repeatedly because some smc_conn_free() from\nserver listening path are not protected by sock lock.\ne.g.\nCalls under socklock | smc_listen_work\n-------------------------------------------------------\nlock_sock(sk) | smc_conn_abort\nsmc_conn_free | \\- smc_conn_free\n\\- smcr_link_put | \\- smcr_link_put (duplicated)\nrelease_sock(sk)\nSo here add sock lock protection in smc_listen_work() path, making it\nexclusive with other connection operations."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, prevent module smc from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically."}, "name": "CVE-2024-56640", "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": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Will not fix", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Will not fix", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-12-27T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2024-56640\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-56640\nhttps://lore.kernel.org/linux-cve-announce/2024122736-CVE-2024-56640-ef22@gregkh/T"], "statement": "The bug happens only when sockets over RDMA being used. It can happen as result of race condition (with function smc_listen_work). The security impact is limited, because could happen only when direct memory access (RDMA) network fabrics being used and for some complex conditions (means that attack complexity is high and requires some authorization for the usage of this protocol).", "threat_severity": "Moderate"}