{"id":"CVE-2025-39767","summary":"LoongArch: Optimize module load time by optimizing PLT/GOT counting","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Optimize module load time by optimizing PLT/GOT counting\n\nWhen enabling CONFIG_KASAN, CONFIG_PREEMPT_VOLUNTARY_BUILD and\nCONFIG_PREEMPT_VOLUNTARY at the same time, there will be soft deadlock,\nthe relevant logs are as follows:\n\nrcu: INFO: rcu_sched self-detected stall on CPU\n...\nCall Trace:\n[\u003c900000000024f9e4\u003e] show_stack+0x5c/0x180\n[\u003c90000000002482f4\u003e] dump_stack_lvl+0x94/0xbc\n[\u003c9000000000224544\u003e] rcu_dump_cpu_stacks+0x1fc/0x280\n[\u003c900000000037ac80\u003e] rcu_sched_clock_irq+0x720/0xf88\n[\u003c9000000000396c34\u003e] update_process_times+0xb4/0x150\n[\u003c90000000003b2474\u003e] tick_nohz_handler+0xf4/0x250\n[\u003c9000000000397e28\u003e] __hrtimer_run_queues+0x1d0/0x428\n[\u003c9000000000399b2c\u003e] hrtimer_interrupt+0x214/0x538\n[\u003c9000000000253634\u003e] constant_timer_interrupt+0x64/0x80\n[\u003c9000000000349938\u003e] __handle_irq_event_percpu+0x78/0x1a0\n[\u003c9000000000349a78\u003e] handle_irq_event_percpu+0x18/0x88\n[\u003c9000000000354c00\u003e] handle_percpu_irq+0x90/0xf0\n[\u003c9000000000348c74\u003e] handle_irq_desc+0x94/0xb8\n[\u003c9000000001012b28\u003e] handle_cpu_irq+0x68/0xa0\n[\u003c9000000001def8c0\u003e] handle_loongarch_irq+0x30/0x48\n[\u003c9000000001def958\u003e] do_vint+0x80/0xd0\n[\u003c9000000000268a0c\u003e] kasan_mem_to_shadow.part.0+0x2c/0x2a0\n[\u003c90000000006344f4\u003e] __asan_load8+0x4c/0x120\n[\u003c900000000025c0d0\u003e] module_frob_arch_sections+0x5c8/0x6b8\n[\u003c90000000003895f0\u003e] load_module+0x9e0/0x2958\n[\u003c900000000038b770\u003e] __do_sys_init_module+0x208/0x2d0\n[\u003c9000000001df0c34\u003e] do_syscall+0x94/0x190\n[\u003c900000000024d6fc\u003e] handle_syscall+0xbc/0x158\n\nAfter analysis, this is because the slow speed of loading the amdgpu\nmodule leads to the long time occupation of the cpu and then the soft\ndeadlock.\n\nWhen loading a module, module_frob_arch_sections() tries to figure out\nthe number of PLTs/GOTs that will be needed to handle all the RELAs. It\nwill call the count_max_entries() to find in an out-of-order date which\ncounting algorithm has O(n^2) complexity.\n\nTo make it faster, we sort the relocation list by info and addend. That\nway, to check for a duplicate relocation, it just needs to compare with\nthe previous entry. This reduces the complexity of the algorithm to O(n\n log n), as done in commit d4e0340919fb (\"arm64/module: Optimize module\nload time by optimizing PLT counting\"). This gives sinificant reduction\nin module load time for modules with large number of relocations.\n\nAfter applying this patch, the soft deadlock problem has been solved,\nand the kernel starts normally without \"Call Trace\".\n\nUsing the default configuration to test some modules, the results are as\nfollows:\n\nModule              Size\nip_tables           36K\nfat                 143K\nradeon              2.5MB\namdgpu              16MB\n\nWithout this patch:\nModule              Module load time (ms)\tCount(PLTs/GOTs)\nip_tables           18\t\t\t\t59/6\nfat                 0\t\t\t\t162/14\nradeon              54\t\t\t\t1221/84\namdgpu              1411\t\t\t4525/1098\n\nWith this patch:\nModule              Module load time (ms)\tCount(PLTs/GOTs)\nip_tables           18\t\t\t\t59/6\nfat                 0\t\t\t\t162/14\nradeon              22\t\t\t\t1221/84\namdgpu              45\t\t\t\t4525/1098","modified":"2026-03-20T12:43:02.681982Z","published":"2025-09-11T16:56:22.238Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39767.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5189c0b7c251363a4dd7678ed11b054c54f36f6f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/63dbd8fb2af3a89466538599a9acb2d11ef65c06"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a096b0280168d0c8b0ec1cbbfd56c8b81af8c7d8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e94cdb9fb279430cbd323a74c7ec124c85109747"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39767.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39767"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fcdfe9d22bed08409968a751e93112f742208be6"},{"fixed":"5189c0b7c251363a4dd7678ed11b054c54f36f6f"},{"fixed":"e94cdb9fb279430cbd323a74c7ec124c85109747"},{"fixed":"a096b0280168d0c8b0ec1cbbfd56c8b81af8c7d8"},{"fixed":"63dbd8fb2af3a89466538599a9acb2d11ef65c06"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39767.json"}}],"schema_version":"1.7.5"}