CVE-2025-21895

{"id": "CVE-2025-21895", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.7, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.0}]}, "published": "2025-04-01T16:15:19.883", "references": [{"url": "https://git.kernel.org/stable/c/2016066c66192a99d9e0ebf433789c490a6785a2", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/3e812a70732d84b7873cea61a7f6349b9a9dcbf5", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/7d582eb6e4e100959ba07083d7563453c8c2a343", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f0c3971405cef6892844016aa710121a02da3a23", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-362"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Order the PMU list to fix warning about unordered pmu_ctx_list\n\nSyskaller triggers a warning due to prev_epc->pmu != next_epc->pmu in\nperf_event_swap_task_ctx_data(). vmcore shows that two lists have the same\nperf_event_pmu_context, but not in the same order.\n\nThe problem is that the order of pmu_ctx_list for the parent is impacted by\nthe time when an event/PMU is added. While the order for a child is\nimpacted by the event order in the pinned_groups and flexible_groups. So\nthe order of pmu_ctx_list in the parent and child may be different.\n\nTo fix this problem, insert the perf_event_pmu_context to its proper place\nafter iteration of the pmu_ctx_list.\n\nThe follow testcase can trigger above warning:\n\n # perf record -e cycles --call-graph lbr -- taskset -c 3 ./a.out &\n # perf stat -e cpu-clock,cs -p xxx // xxx is the pid of a.out\n\n test.c\n\n void main() {\n int count = 0;\n pid_t pid;\n\n printf(\"%d running\\n\", getpid());\n sleep(30);\n printf(\"running\\n\");\n\n pid = fork();\n if (pid == -1) {\n printf(\"fork error\\n\");\n return;\n }\n if (pid == 0) {\n while (1) {\n count++;\n }\n } else {\n while (1) {\n count++;\n }\n }\n }\n\nThe testcase first opens an LBR event, so it will allocate task_ctx_data,\nand then open tracepoint and software events, so the parent context will\nhave 3 different perf_event_pmu_contexts. On inheritance, child ctx will\ninsert the perf_event_pmu_context in another order and the warning will\ntrigger.\n\n[ mingo: Tidied up the changelog. ]"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: perf/core: Ordenar la lista de PMU para corregir la advertencia sobre pmu_ctx_list desordenada Syskaller activa una advertencia debido a prev_epc->pmu != next_epc->pmu en perf_event_swap_task_ctx_data(). vmcore muestra que dos listas tienen el mismo perf_event_pmu_context, pero no en el mismo orden. El problema es que el orden de pmu_ctx_list para el padre se ve afectado por el momento en que se agrega un evento/PMU. Mientras que el orden para un hijo se ve afectado por el orden de los eventos en pinned_groups y flexible_groups. Por lo tanto, el orden de pmu_ctx_list en el padre y el hijo puede ser diferente. Para corregir este problema, inserte perf_event_pmu_context en su lugar correcto despu\u00e9s de la iteraci\u00f3n de pmu_ctx_list. El siguiente caso de prueba puede activar la advertencia anterior: # perf record -e cycles --call-graph lbr -- tasket -c 3 ./a.out & # perf stat -e cpu-clock,cs -p xxx // xxx es el pid de a.out test.c void main() { int count = 0; pid_t pid; printf(\"%d en ejecuci\u00f3n\\n\", getpid()); sleep(30); printf(\"en ejecuci\u00f3n\\n\"); pid = fork(); if (pid == -1) { printf(\"fork error\\n\"); return; } if (pid == 0) { while (1) { count++; } } else { while (1) { count++; } } } El caso de prueba primero abre un evento LBR, por lo que asignar\u00e1 task_ctx_data y luego abrir\u00e1 los eventos de tracepoint y software, por lo que el contexto principal tendr\u00e1 3 perf_event_pmu_contexts diferentes. En caso de herencia, el ctx secundario insertar\u00e1 perf_event_pmu_context en otro orden y se activar\u00e1 la advertencia. [mingo: Se orden\u00f3 el registro de cambios.]"}], "lastModified": "2025-10-31T18:50:50.357", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8C92C9CD-2ADE-412E-A7FF-DC9E0630B25D", "versionEndExcluding": "6.6.81", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3D5C8D9A-4013-4C1A-810F-AA540BB5737C", "versionEndExcluding": "6.12.18", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "64F12D9B-71C2-4CD7-A288-0D5EF1709620", "versionEndExcluding": "6.13.6", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "186716B6-2B66-4BD0-852E-D48E71C0C85F"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0D3E781C-403A-498F-9DA9-ECEE50F41E75"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "66619FB8-0AAF-4166-B2CF-67B24143261D"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D3D6550E-6679-4560-902D-AF52DCFE905B"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}