CVE-2021-47274

{"id": "CVE-2021-47274", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "published": "2024-05-21T15:15:15.830", "references": [{"url": "https://git.kernel.org/stable/c/2d598902799886d67947406f26ee8e5fd2ca097f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/31ceae385556c37e4d286cb6378696448f566883", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/3e08a9f9760f4a70d633c328a76408e62d6f80a3", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/43c32c22254b9328d7abb1c2b0f689dc67838e60", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b16a249eca2230c2cd66fa1d4b94743bd9b6ef92", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d63f00ec908b3be635ead5d6029cc94246e1f38d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/edcce01e0e50840a9aa6a70baed21477bdd2c9f9", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/2d598902799886d67947406f26ee8e5fd2ca097f", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/31ceae385556c37e4d286cb6378696448f566883", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/3e08a9f9760f4a70d633c328a76408e62d6f80a3", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/43c32c22254b9328d7abb1c2b0f689dc67838e60", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/b16a249eca2230c2cd66fa1d4b94743bd9b6ef92", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/d63f00ec908b3be635ead5d6029cc94246e1f38d", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/edcce01e0e50840a9aa6a70baed21477bdd2c9f9", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-125"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Correct the length check which causes memory corruption\n\nWe've suffered from severe kernel crashes due to memory corruption on\nour production environment, like,\n\nCall Trace:\n[1640542.554277] general protection fault: 0000 [#1] SMP PTI\n[1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G\n[1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190\n[1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286\n[1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX:\n0000000006e931bf\n[1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI:\nffff9a45ff004300\n[1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09:\n0000000000000000\n[1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12:\nffffffff9a20608d\n[1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15:\n696c662f65636976\n[1640542.563128] FS: 00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000)\nknlGS:0000000000000000\n[1640542.563937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4:\n00000000003606e0\n[1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2:\n0000000000000000\n[1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:\n0000000000000400\n[1640542.566742] Call Trace:\n[1640542.567009] anon_vma_clone+0x5d/0x170\n[1640542.567417] __split_vma+0x91/0x1a0\n[1640542.567777] do_munmap+0x2c6/0x320\n[1640542.568128] vm_munmap+0x54/0x70\n[1640542.569990] __x64_sys_munmap+0x22/0x30\n[1640542.572005] do_syscall_64+0x5b/0x1b0\n[1640542.573724] entry_SYSCALL_64_after_hwframe+0x44/0xa9\n[1640542.575642] RIP: 0033:0x7f45d6e61e27\n\nJames Wang has reproduced it stably on the latest 4.19 LTS.\nAfter some debugging, we finally proved that it's due to ftrace\nbuffer out-of-bound access using a debug tool as follows:\n[ 86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000\n[ 86.780806] no_context+0xdf/0x3c0\n[ 86.784327] __do_page_fault+0x252/0x470\n[ 86.788367] do_page_fault+0x32/0x140\n[ 86.792145] page_fault+0x1e/0x30\n[ 86.795576] strncpy_from_unsafe+0x66/0xb0\n[ 86.799789] fetch_memory_string+0x25/0x40\n[ 86.804002] fetch_deref_string+0x51/0x60\n[ 86.808134] kprobe_trace_func+0x32d/0x3a0\n[ 86.812347] kprobe_dispatcher+0x45/0x50\n[ 86.816385] kprobe_ftrace_handler+0x90/0xf0\n[ 86.820779] ftrace_ops_assist_func+0xa1/0x140\n[ 86.825340] 0xffffffffc00750bf\n[ 86.828603] do_sys_open+0x5/0x1f0\n[ 86.832124] do_syscall_64+0x5b/0x1b0\n[ 86.835900] entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\ncommit b220c049d519 (\"tracing: Check length before giving out\nthe filter buffer\") adds length check to protect trace data\noverflow introduced in 0fc1b09ff1ff, seems that this fix can't prevent\noverflow entirely, the length check should also take the sizeof\nentry->array[0] into account, since this array[0] is filled the\nlength of trace data and occupy addtional space and risk overflow."}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: rastreo: corrija la verificaci\u00f3n de longitud que causa corrupci\u00f3n de la memoria. Hemos sufrido fallos graves del kernel debido a la corrupci\u00f3n de la memoria en nuestro entorno de producci\u00f3n, como Call Trace: [1640542.554277] fallo de protecci\u00f3n general. : 0000 [#1] SMP PTI [1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: cargado Contaminado:G [1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190 [1640542.559074] : 0018:ffffb16faa597df8 EFLAGS: 00010286 [ 1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX: 0000000006e931bf [1640542.560323] RDX: 0000000006e931be RSI: 0000400200 RDI: ffff9a45ff004300 [1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09: 0000000000000000 [1640542.561670] : 0000000000000000 R11: 0000000000000000 R12: ffffffff9a20608d [1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15: 696c662f65636976 [1640542.563128] FS: 00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000) GS:0000000000000000 [1640542.563937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4: 00000000003606e0 [1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1640542.5 66069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1640542.566742] Seguimiento de llamadas: [1640542.567009] anon_vma_clone+0x5d/0x170 2.567417] __split_vma+0x91/0x1a0 [1640542.567777] do_munmap+0x2c6/0x320 [1640542.568128] vm_munmap+0x54/0x70 [1640542.569990] __x64_sys_munmap+0x22/0x30 [1640542.572005] _64+0x5b/0x1b0 [1640542.573724] entrada_SYSCALL_64_after_hwframe+0x44/0xa9 [1640542.575642] RIP: 0033:0x7f45d6e61e27 James Wang lo ha reproducido de forma estable en la \u00faltima versi\u00f3n 4.19 LTS. Despu\u00e9s de algunas depuraciones, finalmente demostramos que se debe al acceso fuera de los l\u00edmites al b\u00fafer ftrace usando una herramienta de depuraci\u00f3n de la siguiente manera: [86.775200] ERROR: Escritura fuera de los l\u00edmites en la direcci\u00f3n 0xffff88aefe8b7000 [86.780806] no_context+0xdf/0x3c0 [86.784327 ] __do_page_fault+0x252/0x470 [ 86.788367] do_page_fault+0x32/0x140 [ 86.792145] page_fault+0x1e/0x30 [ 86.795576] strncpy_from_unsafe+0x66/0xb0 [ 86.799789] ry_string+0x25/0x40 [ 86.804002] fetch_deref_string+0x51/0x60 [ 86.808134] kprobe_trace_func +0x32d/0x3a0 [ 86.812347] kprobe_dispatcher+0x45/0x50 [ 86.816385] kprobe_ftrace_handler+0x90/0xf0 [ 86.820779] ftrace_ops_assist_func+0xa1/0x140 [ 86.825340] ffffc00750bf [ 86.828603] do_sys_open+0x5/0x1f0 [ 86.832124] do_syscall_64+0x5b/0x1b0 [ 86.835900 ] Entry_SYSCALL_64_after_hwframe+0x44/0xa9 commit b220c049d519 (\"rastreo: verificar la longitud antes de entregar el b\u00fafer de filtro\") agrega verificaci\u00f3n de longitud para proteger el desbordamiento de datos de seguimiento introducido en 0fc1b09ff1ff, parece que esta soluci\u00f3n no puede evitar el desbordamiento por completo, la verificaci\u00f3n de longitud tambi\u00e9n deber\u00eda tenga en cuenta el tama\u00f1o de la entrada->matriz[0], ya que esta matriz[0] ocupa toda la longitud de los datos de seguimiento y ocupa espacio adicional y corre el riesgo de desbordarse."}], "lastModified": "2025-04-04T14:29:40.560", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D73EA9B8-6293-4837-B511-DAD9DBFA5636", "versionEndExcluding": "4.9.273", "versionStartIncluding": "4.9.258"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "678E7D52-5CA6-4608-8727-D74ED21A45B5", "versionEndExcluding": "4.14.237", "versionStartIncluding": "4.14.222"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "12CD72A1-696C-421C-AD11-87E6942FC473", "versionEndExcluding": "4.19.195", "versionStartIncluding": "4.19.177"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6423589E-DA2E-4EA5-8738-C64751B2DAC9", "versionEndExcluding": "5.4.126", "versionStartIncluding": "5.4.99"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1A5F40E7-CF49-4CBA-90AF-0CAA330EEC45", "versionEndExcluding": "5.10.44", "versionStartIncluding": "5.10.17"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F914A757-FAFD-407E-9031-21F66635D5EA", "versionEndExcluding": "5.12.11", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0CBAD0FC-C281-4666-AB2F-F8E6E1165DF7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "96AC23B2-D46A-49D9-8203-8E1BEDCA8532"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DA610E30-717C-4700-9F77-A3C9244F3BFD"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1ECD33F5-85BE-430B-8F86-8D7BD560311D"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CF351855-2437-4CF5-AD7C-BDFA51F27683"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}