CVE-2023-52443

{"id": "CVE-2023-52443", "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": "2024-02-22T17:15:08.377", "references": [{"url": "https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/77ab09b92f16c8439a948d1af489196953dc4a0e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9286ee97aa4803d99185768735011d0d65827c9e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9d4fa5fe2b1d56662afd14915a73b4d0783ffa45", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00016.html", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: avoid crash when parsed profile name is empty\n\nWhen processing a packed profile in unpack_profile() described like\n\n \"profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}\"\n\na string \":samba-dcerpcd\" is unpacked as a fully-qualified name and then\npassed to aa_splitn_fqname().\n\naa_splitn_fqname() treats \":samba-dcerpcd\" as only containing a namespace.\nThus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later\naa_alloc_profile() crashes as the new profile name is NULL now.\n\ngeneral protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nCPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014\nRIP: 0010:strlen+0x1e/0xa0\nCall Trace:\n <TASK>\n ? strlen+0x1e/0xa0\n aa_policy_init+0x1bb/0x230\n aa_alloc_profile+0xb1/0x480\n unpack_profile+0x3bc/0x4960\n aa_unpack+0x309/0x15e0\n aa_replace_profiles+0x213/0x33c0\n policy_update+0x261/0x370\n profile_replace+0x20e/0x2a0\n vfs_write+0x2af/0xe00\n ksys_write+0x126/0x250\n do_syscall_64+0x46/0xf0\n entry_SYSCALL_64_after_hwframe+0x6e/0x76\n </TASK>\n---[ end trace 0000000000000000 ]---\nRIP: 0010:strlen+0x1e/0xa0\n\nIt seems such behaviour of aa_splitn_fqname() is expected and checked in\nother places where it is called (e.g. aa_remove_profiles). Well, there\nis an explicit comment \"a ns name without a following profile is allowed\"\ninside.\n\nAFAICS, nothing can prevent unpacked \"name\" to be in form like\n\":samba-dcerpcd\" - it is passed from userspace.\n\nDeny the whole profile set replacement in such case and inform user with\nEPROTO and an explaining message.\n\nFound by Linux Verification Center (linuxtesting.org)."}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: apparmor: evita fallas cuando el nombre del perfil analizado est\u00e1 vac\u00edo Al procesar un perfil empaquetado en unpack_profile() descrito como \"perfil :ns::samba-dcerpcd /usr/lib*/samba/ {,samba/}samba-dcerpcd {...}\" una cadena \":samba-dcerpcd\" se descomprime como un nombre completo y luego se pasa a aa_splitn_fqname(). aa_splitn_fqname() trata \":samba-dcerpcd\" como si solo contuviera un espacio de nombres. Por lo tanto, devuelve NULL para tmpname, mientras que tmpns no es NULL. M\u00e1s tarde, aa_alloc_profile() falla porque el nuevo nombre del perfil ahora es NULL. falla de protecci\u00f3n general, probablemente para direcci\u00f3n no can\u00f3nica 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref en rango [0x00000000000000000-0x0000000000000007] CPU: 6 PID: 1657 Comm: apparmor_parser No contaminado 6.7.0- rc2-dirty #16 Nombre del hardware: PC est\u00e1ndar QEMU (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 01/04/2014 RIP: 0010:strlen+0x1e/0xa0 Llamada Seguimiento: ? strlen+0x1e/0xa0 aa_policy_init+0x1bb/0x230 aa_alloc_profile+0xb1/0x480 unpack_profile+0x3bc/0x4960 aa_unpack+0x309/0x15e0 aa_replace_profiles+0x213/0x33c0 Policy_update+0x261/0x370 perfil_replace+ 0x20e/0x2a0 vfs_write+0x2af/0xe00 ksys_write+0x126/0x250 do_syscall_64+0x46/0xf0 Entry_SYSCALL_64_after_hwframe+0x6e/0x76 ---[ end trace 0000000000000000 ]--- RIP: 0010:strlen+0x1e/0xa0 Parece que tal comportamiento de aa_splitn_fqname() se espera y se verifica en otros lugares donde se llama (por ejemplo, aa_remove_profiles). Bueno, hay un comentario expl\u00edcito \"se permite un nombre ns sin un perfil de seguimiento\" dentro. AFAICS, nada puede evitar que el \"nombre\" descomprimido tenga un formato como \":samba-dcerpcd\": se pasa desde el espacio de usuario. En tal caso, rechace el reemplazo completo del conjunto de perfiles e informe al usuario con EPROTO y un mensaje explicativo. Encontrado por el Centro de verificaci\u00f3n de Linux (linuxtesting.org)."}], "lastModified": "2024-06-27T12:15:14.257", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0A7AEFD0-0681-4E8D-9074-27416D3EE94C", "versionEndExcluding": "4.19.306"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "991BF737-6083-429B-ACD5-FB27D4143E2F", "versionEndExcluding": "5.4.268", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5D2E4F24-2FBB-4434-8598-2B1499E566B5", "versionEndExcluding": "5.10.209", "versionStartIncluding": "5.5.0"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E25E1389-4B0F-407A-9C94-5908FF3EE88B", "versionEndExcluding": "5.15.148", "versionStartIncluding": "5.11.0"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2C4951FA-80C0-4B4C-9836-6E5035DEB0F9", "versionEndExcluding": "6.1.75", "versionStartIncluding": "5.16.0"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BDBBEB0E-D13A-4567-8984-51C5375350B9", "versionEndExcluding": "6.6.14", "versionStartIncluding": "6.2.0"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0EA3778C-730B-464C-8023-18CA6AC0B807", "versionEndExcluding": "6.7.2", "versionStartIncluding": "6.7.0"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}