CVE-2025-21910

{"id": "CVE-2025-21910", "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": "2025-04-01T16:15:21.550", "references": [{"url": "https://git.kernel.org/stable/c/17aa34c84867f6cd181a5743e1c647e7766962a6", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/35ef07112b61b06eb30683a6563c9f6378c02476", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/59b348be7597c4a9903cb003c69e37df20c04a30", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/62b1a9bbfebba4b4c2bb6c1ede9ef7ecee7a9ff6", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/6a5e3b23054cee3b92683d1467e3fa83921f5622", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/be7c5f00aa7f1344293e4d48d0e12be83a2f223d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/da3f599517ef2ea851208df3229d07728d238dc5", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f4112cb477c727a65787a4065a75ca593bb5b2f4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: cfg80211: regulatory: improve invalid hints checking\n\nSyzbot keeps reporting an issue [1] that occurs when erroneous symbols\nsent from userspace get through into user_alpha2[] via\nregulatory_hint_user() call. Such invalid regulatory hints should be\nrejected.\n\nWhile a sanity check from commit 47caf685a685 (\"cfg80211: regulatory:\nreject invalid hints\") looks to be enough to deter these very cases,\nthere is a way to get around it due to 2 reasons.\n\n1) The way isalpha() works, symbols other than latin lower and\nupper letters may be used to determine a country/domain.\nFor instance, greek letters will also be considered upper/lower\nletters and for such characters isalpha() will return true as well.\nHowever, ISO-3166-1 alpha2 codes should only hold latin\ncharacters.\n\n2) While processing a user regulatory request, between\nreg_process_hint_user() and regulatory_hint_user() there happens to\nbe a call to queue_regulatory_request() which modifies letters in\nrequest->alpha2[] with toupper(). This works fine for latin symbols,\nless so for weird letter characters from the second part of _ctype[].\n\nSyzbot triggers a warning in is_user_regdom_saved() by first sending\nover an unexpected non-latin letter that gets malformed by toupper()\ninto a character that ends up failing isalpha() check.\n\nPrevent this by enhancing is_an_alpha2() to ensure that incoming\nsymbols are latin letters and nothing else.\n\n[1] Syzbot report:\n------------[ cut here ]------------\nUnexpected user alpha2: A\ufffd\nWARNING: CPU: 1 PID: 964 at net/wireless/reg.c:442 is_user_regdom_saved net/wireless/reg.c:440 [inline]\nWARNING: CPU: 1 PID: 964 at net/wireless/reg.c:442 restore_alpha2 net/wireless/reg.c:3424 [inline]\nWARNING: CPU: 1 PID: 964 at net/wireless/reg.c:442 restore_regulatory_settings+0x3c0/0x1e50 net/wireless/reg.c:3516\nModules linked in:\nCPU: 1 UID: 0 PID: 964 Comm: kworker/1:2 Not tainted 6.12.0-rc5-syzkaller-00044-gc1e939a21eb1 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\nWorkqueue: events_power_efficient crda_timeout_work\nRIP: 0010:is_user_regdom_saved net/wireless/reg.c:440 [inline]\nRIP: 0010:restore_alpha2 net/wireless/reg.c:3424 [inline]\nRIP: 0010:restore_regulatory_settings+0x3c0/0x1e50 net/wireless/reg.c:3516\n...\nCall Trace:\n <TASK>\n crda_timeout_work+0x27/0x50 net/wireless/reg.c:542\n process_one_work kernel/workqueue.c:3229 [inline]\n process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310\n worker_thread+0x870/0xd30 kernel/workqueue.c:3391\n kthread+0x2f2/0x390 kernel/kthread.c:389\n ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n </TASK>"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: wifi: cfg80211: regulatory: improve invalid hints checking Syzbot sigue reportando un problema [1] que ocurre cuando s\u00edmbolos err\u00f3neos enviados desde el espacio de usuario se introducen en user_alpha2[] mediante la llamada regulatory_hint_user(). Estas sugerencias regulatorias inv\u00e1lidas deben rechazarse. Si bien una comprobaci\u00f3n de seguridad del commit 47caf685a685 (\"cfg80211: regulatory: reject invalid hints\") parece ser suficiente para evitar estos casos, existe una forma de evitarla por dos razones: 1) El funcionamiento de isalpha() permite usar s\u00edmbolos distintos de las letras latinas may\u00fasculas y min\u00fasculas para determinar un pa\u00eds o dominio. Por ejemplo, las letras griegas tambi\u00e9n se considerar\u00e1n may\u00fasculas y min\u00fasculas, y para estos caracteres isalpha() tambi\u00e9n devolver\u00e1 verdadero. Sin embargo, los c\u00f3digos ISO-3166-1 alpha2 solo deben contener caracteres latinos. 2) Al procesar una solicitud regulatoria de usuario, entre reg_process_hint_user() y regulatory_hint_user() se produce una llamada a queue_regulatory_request() que modifica las letras en request-&gt;alpha2[] con toupper(). Esto funciona correctamente con s\u00edmbolos latinos, pero no tanto con caracteres de letras extra\u00f1as de la segunda parte de _ctype[]. Syzbot genera una advertencia en is_user_regdom_saved() al enviar primero una letra no latina inesperada que toupper() malforma en un car\u00e1cter que falla la comprobaci\u00f3n de isalpha(). Para evitar esto, mejore is_an_alpha2() para garantizar que los s\u00edmbolos entrantes sean \u00fanicamente letras latinas. [1] Informe de Syzbot: ------------[ cortar aqu\u00ed ]------------ Usuario inesperado alpha2: A? ADVERTENCIA: CPU: 1 PID: 964 en net/wireless/reg.c:442 is_user_regdom_saved net/wireless/reg.c:440 [en l\u00ednea] ADVERTENCIA: CPU: 1 PID: 964 en net/wireless/reg.c:442 restore_alpha2 net/wireless/reg.c:3424 [en l\u00ednea] ADVERTENCIA: CPU: 1 PID: 964 en net/wireless/reg.c:442 restore_regulatory_settings+0x3c0/0x1e50 net/wireless/reg.c:3516 M\u00f3dulos vinculados: CPU: 1 UID: 0 PID: 964 Comm: kworker/1:2 No contaminado 6.12.0-rc5-syzkaller-00044-gc1e939a21eb1 #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 13/09/2024 Cola de trabajo: events_power_efficient crda_timeout_work RIP: 0010:is_user_regdom_saved net/wireless/reg.c:440 [en l\u00ednea] RIP: 0010:restore_alpha2 net/wireless/reg.c:3424 [en l\u00ednea] RIP: 0010:restore_regulatory_settings+0x3c0/0x1e50 net/wireless/reg.c:3516 ... Rastreo de llamadas: crda_timeout_work+0x27/0x50 net/wireless/reg.c:542 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 "}], "lastModified": "2025-10-31T18:04:40.817", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "EED05E52-7CFA-4A43-A352-40F047FDB63A", "versionEndExcluding": "5.4.291", "versionStartIncluding": "2.6.34"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "545121FA-DE31-4154-9446-C2000FB4104D", "versionEndExcluding": "5.10.235", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C708062C-4E1B-465F-AE6D-C09C46400875", "versionEndExcluding": "5.15.179", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BA9C2DE3-D37C-46C6-8DCD-2EE509456E0B", "versionEndExcluding": "6.1.131", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7D9F642F-6E05-4926-B0FE-62F95B7266BC", "versionEndExcluding": "6.6.83", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "32865E5C-8AE1-4D3D-A64D-299039694A88", "versionEndExcluding": "6.12.19", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "842F5A44-3E71-4546-B4FD-43B0ACE3F32B", "versionEndExcluding": "6.13.7", "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"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "45B90F6B-BEC7-4D4E-883A-9DBADE021750"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}