CVE-2026-23127

{"id": "CVE-2026-23127", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2026-02-14T15:16:07.963", "references": [{"url": "https://git.kernel.org/stable/c/23c0e4bd93d0b250775162faf456470485ac9fc7", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d06bf78e55d5159c1b00072e606ab924ffbbad35", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-Other"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf: Fix refcount warning on event->mmap_count increment\n\nWhen calling refcount_inc(&event->mmap_count) inside perf_mmap_rb(), the\nfollowing warning is triggered:\n\n refcount_t: addition on 0; use-after-free.\n WARNING: lib/refcount.c:25\n\nPoC:\n\n struct perf_event_attr attr = {0};\n int fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);\n mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);\n int victim = syscall(__NR_perf_event_open, &attr, 0, -1, fd,\n PERF_FLAG_FD_OUTPUT);\n mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, victim, 0);\n\nThis occurs when creating a group member event with the flag\nPERF_FLAG_FD_OUTPUT. The group leader should be mmap-ed and then mmap-ing\nthe event triggers the warning.\n\nSince the event has copied the output_event in perf_event_set_output(),\nevent->rb is set. As a result, perf_mmap_rb() calls\nrefcount_inc(&event->mmap_count) when event->mmap_count = 0.\n\nDisallow the case when event->mmap_count = 0. This also prevents two\nevents from updating the same user_page."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nperf: Correcci\u00f3n de la advertencia de refcount en el incremento de event->mmap_count\n\nAl llamar a refcount_inc(&event->mmap_count) dentro de perf_mmap_rb(), se activa la siguiente advertencia:\n\n refcount_t: adici\u00f3n en 0; uso despu\u00e9s de liberaci\u00f3n.\n ADVERTENCIA: lib/refcount.c:25\n\nPoC:\n\n struct perf_event_attr attr = {0};\n int fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);\n mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);\n int victim = syscall(__NR_perf_event_open, &attr, 0, -1, fd,\n PERF_FLAG_FD_OUTPUT);\n mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, victim, 0);\n\nEsto ocurre al crear un evento miembro de grupo con la bandera PERF_FLAG_FD_OUTPUT. El l\u00edder del grupo debe ser mapeado con mmap y luego mapear el evento con mmap activa la advertencia.\n\nDado que el evento ha copiado el output_event en perf_event_set_output(), event->rb est\u00e1 establecido. Como resultado, perf_mmap_rb() llama a refcount_inc(&event->mmap_count) cuando event->mmap_count = 0.\n\nNo permitir el caso cuando event->mmap_count = 0. Esto tambi\u00e9n evita que dos eventos actualicen la misma user_page."}], "lastModified": "2026-03-18T14:49:58.400", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7B26C1E1-97A9-48B8-81C6-B6A3A0FC6C7E", "versionEndExcluding": "6.18.8", "versionStartIncluding": "6.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "17B67AA7-40D6-4AFA-8459-F200F3D7CFD1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C47E4CC9-C826-4FA9-B014-7FE3D9B318B2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F71D92C0-C023-48BD-B3B6-70B638EEE298"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "13580667-0A98-40CC-B29F-D12790B91BDB"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CAD1FED7-CF48-47BF-AC7D-7B6FA3C065FC"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3EF854A1-ABB1-4E93-BE9A-44569EC76C0D"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}