CVE-2023-52523

{"id": "CVE-2023-52523", "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": "2024-03-02T22:15:48.213", "references": [{"url": "https://git.kernel.org/stable/c/b80e31baa43614e086a9d29dc1151932b1bd7fc5", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b8f97e47b6fb84fcf2f5a22e725eefb6cf5070c2", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/bc8b89b6963803a123f64aa9494155a037b3d728", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ded6e448028f0f91b6af35985afca01fa02a9089", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b80e31baa43614e086a9d29dc1151932b1bd7fc5", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/b8f97e47b6fb84fcf2f5a22e725eefb6cf5070c2", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/bc8b89b6963803a123f64aa9494155a037b3d728", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/ded6e448028f0f91b6af35985afca01fa02a9089", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "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\nbpf, sockmap: Reject sk_msg egress redirects to non-TCP sockets\n\nWith a SOCKMAP/SOCKHASH map and an sk_msg program user can steer messages\nsent from one TCP socket (s1) to actually egress from another TCP\nsocket (s2):\n\ntcp_bpf_sendmsg(s1)\t\t// = sk_prot->sendmsg\n tcp_bpf_send_verdict(s1)\t// __SK_REDIRECT case\n tcp_bpf_sendmsg_redir(s2)\n tcp_bpf_push_locked(s2)\n\ttcp_bpf_push(s2)\n\t tcp_rate_check_app_limited(s2) // expects tcp_sock\n\t tcp_sendmsg_locked(s2)\t // ditto\n\nThere is a hard-coded assumption in the call-chain, that the egress\nsocket (s2) is a TCP socket.\n\nHowever in commit 122e6c79efe1 (\"sock_map: Update sock type checks for\nUDP\") we have enabled redirects to non-TCP sockets. This was done for the\nsake of BPF sk_skb programs. There was no indention to support sk_msg\nsend-to-egress use case.\n\nAs a result, attempts to send-to-egress through a non-TCP socket lead to a\ncrash due to invalid downcast from sock to tcp_sock:\n\n BUG: kernel NULL pointer dereference, address: 000000000000002f\n ...\n Call Trace:\n <TASK>\n ? show_regs+0x60/0x70\n ? __die+0x1f/0x70\n ? page_fault_oops+0x80/0x160\n ? do_user_addr_fault+0x2d7/0x800\n ? rcu_is_watching+0x11/0x50\n ? exc_page_fault+0x70/0x1c0\n ? asm_exc_page_fault+0x27/0x30\n ? tcp_tso_segs+0x14/0xa0\n tcp_write_xmit+0x67/0xce0\n __tcp_push_pending_frames+0x32/0xf0\n tcp_push+0x107/0x140\n tcp_sendmsg_locked+0x99f/0xbb0\n tcp_bpf_push+0x19d/0x3a0\n tcp_bpf_sendmsg_redir+0x55/0xd0\n tcp_bpf_send_verdict+0x407/0x550\n tcp_bpf_sendmsg+0x1a1/0x390\n inet_sendmsg+0x6a/0x70\n sock_sendmsg+0x9d/0xc0\n ? sockfd_lookup_light+0x12/0x80\n __sys_sendto+0x10e/0x160\n ? syscall_enter_from_user_mode+0x20/0x60\n ? __this_cpu_preempt_check+0x13/0x20\n ? lockdep_hardirqs_on+0x82/0x110\n __x64_sys_sendto+0x1f/0x30\n do_syscall_64+0x38/0x90\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nReject selecting a non-TCP sockets as redirect target from a BPF sk_msg\nprogram to prevent the crash. When attempted, user will receive an EACCES\nerror from send/sendto/sendmsg() syscall."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf, sockmap: rechaza las redirecciones de salida de sk_msg a sockets que no son TCP. Con un mapa SOCKMAP/SOCKHASH y un programa sk_msg, el usuario puede dirigir los mensajes enviados desde un socket TCP (s1) para que realmente salgan desde otro socket TCP (s2): tcp_bpf_sendmsg(s1) // = sk_prot-&gt;sendmsg tcp_bpf_send_verdict(s1) // __SK_REDIRECT caso tcp_bpf_sendmsg_redir(s2) tcp_bpf_push_locked(s2) tcp_bpf_push(s2) tcp_rate_check_ app_limited(s2) // espera tcp_sock tcp_sendmsg_locked(s2 ) // \u00eddem Hay una suposici\u00f3n codificada en la cadena de llamadas de que el socket de salida (s2) es un socket TCP. Sin embargo, en el commit 122e6c79efe1 (\"sock_map: Actualizar comprobaciones de tipo de calcet\u00edn para UDP\") hemos habilitado redirecciones a sockets que no son TCP. Esto se hizo por el bien de los programas BPF sk_skb. No hab\u00eda ninguna sangr\u00eda para admitir el caso de uso de env\u00edo a salida de sk_msg. Como resultado, los intentos de env\u00edo a salida a trav\u00e9s de un socket que no es TCP provocan un bloqueo debido a una conversi\u00f3n no v\u00e1lida de sock a tcp_sock: ERROR: desreferencia del puntero NULL del n\u00facleo, direcci\u00f3n: 0000000000000002f... Seguimiento de llamadas: . mostrar_regs+0x60/0x70? __die+0x1f/0x70 ? page_fault_oops+0x80/0x160? do_user_addr_fault+0x2d7/0x800? rcu_is_watching+0x11/0x50? exc_page_fault+0x70/0x1c0? asm_exc_page_fault+0x27/0x30? tcp_tso_segs+0x14/0xa0 tcp_write_xmit+0x67/0xce0 __tcp_push_pending_frames+0x32/0xf0 tcp_push+0x107/0x140 tcp_sendmsg_locked+0x99f/0xbb0 tcp_bpf_push+0x19d/0x3a0 tcp_bpf_sendmsg_redir+0x55/0xd0 tcp_bpf_send_verdict+0x407/0x550 tcp_bpf_sendmsg+0x1a1/0x390 inet_sendmsg+0x6a/0x70 sock_sendmsg+0x9d/0xc0? sockfd_lookup_light+0x12/0x80 __sys_sendto+0x10e/0x160 ? syscall_enter_from_user_mode+0x20/0x60? __this_cpu_preempt_check+0x13/0x20? lockdep_hardirqs_on+0x82/0x110 __x64_sys_sendto+0x1f/0x30 do_syscall_64+0x38/0x90 Entry_SYSCALL_64_after_hwframe+0x63/0xcd Rechace la selecci\u00f3n de sockets que no sean TCP como destino de redireccionamiento desde un programa BPF sk_msg para evitar el bloqueo. Cuando lo intente, el usuario recibir\u00e1 un error EACCES de la llamada al sistema send/sendto/sendmsg()."}], "lastModified": "2025-01-13T19:57:06.317", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0988674C-BFC5-4018-840B-F6E3C9B45A62", "versionEndExcluding": "5.15.135", "versionStartIncluding": "5.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8629E5D1-351D-4D4B-8D05-E10BD4A1CFD0", "versionEndExcluding": "6.1.57", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "830A824C-F212-4FDC-ADEF-0EBEC6B2365B", "versionEndExcluding": "6.5.7", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.6:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "84267A4F-DBC2-444F-B41D-69E15E1BEC97"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.6:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FB440208-241C-4246-9A83-C1715C0DAA6C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.6:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0DC421F1-3D5A-4BEF-BF76-4E468985D20B"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.6:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "00AB783B-BE05-40E8-9A55-6AA457D95031"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}