CVE-2026-43409

/* * Conceptual PoC for CVE-2026-43409 * This requires a kernel environment where ftrace can be killed or simulated. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/kprobes.h> static struct kprobe kp; // Example handler static int handler_pre(struct kprobe *p, struct pt_regs *regs) { return 0; } static int __init init_module(void) { kp.pre_handler = handler_pre; kp.symbol_name = "do_sys_open"; // Example symbol register_kprobe(&kp); printk(KERN_INFO "Kprobe registered\n"); return 0; } static void __exit cleanup_module(void) { unregister_kprobe(&kp); printk(KERN_INFO "Kprobe unregistered\n"); } /* * Steps to reproduce: * 1. Load this module. * 2. Trigger ftrace_kill() (e.g., via another vulnerability or debug interface). * 3. Run 'rmmod [module_name]'. * 4. Kernel Oops occurs due to missing check in __disarm_kprobe_ftrace. */

{"cve": {"id": "CVE-2026-43409", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T15:16:52.513", "lastModified": "2026-05-21T19:03:05.780", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkprobes: avoid crash when rmmod/insmod after ftrace killed\n\nAfter we hit ftrace is killed by some errors, the kernel crash if\nwe remove modules in which kprobe probes.\n\nBUG: unable to handle page fault for address: fffffbfff805000d\nPGD 817fcc067 P4D 817fcc067 PUD 817fc8067 PMD 101555067 PTE 0\nOops: Oops: 0000 [#1] SMP KASAN PTI\nCPU: 4 UID: 0 PID: 2012 Comm: rmmod Tainted: G W OE\nTainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\nRIP: 0010:kprobes_module_callback+0x89/0x790\nRSP: 0018:ffff88812e157d30 EFLAGS: 00010a02\nRAX: 1ffffffff805000d RBX: dffffc0000000000 RCX: ffffffff86a8de90\nRDX: ffffed1025c2af9b RSI: 0000000000000008 RDI: ffffffffc0280068\nRBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1025c2af9a\nR10: ffff88812e157cd7 R11: 205d323130325420 R12: 0000000000000002\nR13: ffffffffc0290488 R14: 0000000000000002 R15: ffffffffc0280040\nFS: 00007fbc450dd740(0000) GS:ffff888420331000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: fffffbfff805000d CR3: 000000010f624000 CR4: 00000000000006f0\nCall Trace:\n <TASK>\n notifier_call_chain+0xc6/0x280\n blocking_notifier_call_chain+0x60/0x90\n __do_sys_delete_module.constprop.0+0x32a/0x4e0\n do_syscall_64+0x5d/0xfa0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThis is because the kprobe on ftrace does not correctly handles\nthe kprobe_ftrace_disabled flag set by ftrace_kill().\n\nTo prevent this error, check kprobe_ftrace_disabled in\n__disarm_kprobe_ftrace() and skip all ftrace related operations."}], "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": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7", "versionEndExcluding": "6.6.130", "matchCriteriaId": "C5F51C67-AAE9-4581-82CD-44F5AF217183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.78", "matchCriteriaId": "28D591F5-B196-4CC9-905C-DC80F116E7A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.19", "matchCriteriaId": "D394AC60-6F28-435F-872A-CCDF384B8331"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.9", "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/8b6767e4141b2a42745b544d4555cf1614ba1a2d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/9edc79d664832a842012ad105b1521c1a3c35ab3", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/b0ca81616a010807e91fc31db9be242b96326adc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/cae928e3178c75602c21d67e21255d73e7e9ed4f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/e113f0b46d19626ec15388bcb91432c9a4fd6261", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}