{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-45856", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.079Z", "datePublished": "2026-05-27T12:15:33.209Z", "dateUpdated": "2026-10-16T15:20:44.029Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:28:29.851Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send\n\nib_uverbs_post_send() uses cmd.wqe_size from userspace without any\nvalidation before passing it to kmalloc() and using the allocated\nbuffer as struct ib_uverbs_send_wr.\n\nIf a user provides a small wqe_size value (e.g., 1), kmalloc() will\nsucceed, but subsequent accesses to user_wr->opcode, user_wr->num_sge,\nand other fields will read beyond the allocated buffer, resulting in\nan out-of-bounds read from kernel heap memory. This could potentially\nleak sensitive kernel information to userspace.\n\nAdditionally, providing an excessively large wqe_size can trigger a\nWARNING in the memory allocation path, as reported by syzkaller.\n\nThis is inconsistent with ib_uverbs_unmarshall_recv() which properly\nvalidates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before\nproceeding.\n\nAdd the same validation for ib_uverbs_post_send() to ensure wqe_size\nis at least sizeof(struct ib_uverbs_send_wr)." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is reached via write() on the local RDMA uverbs character device (/dev/infiniband/uverbs*) dispatched through UAPI_DEF_WRITE_IO; it is not reachable over any network.\nAC:L - The attacker fully controls cmd.wqe_size and can reliably trigger the OOB read by simply setting wqe_size=1 (or the WARN with a huge value); no uncontrolled conditions are involved.\nPR:L - An unprivileged local user with access to the RDMA uverbs device (the normal case on RDMA-enabled systems, and obtainable via Soft-RoCE) can open a context, create a QP, and issue POST_SEND; no real-root privilege is required.\nUI:N - The command is issued directly by the attacker via a syscall; no action by any other user is needed.\nS:U - The OOB read and resulting impact remain within the kernel's own security authority; no crossing of a security boundary (VM/IOMMU/sandbox) occurs.\nC:H - The bug reads ~48 bytes of kernel heap memory beyond the undersized allocation, and the leaked values (e.g. wr_id) are returned to userspace via completion polling, giving a repeatable kernel-heap information disclosure.\nI:N - The defect is purely an out-of-bounds read; num_sge is bounded by the sge_count check, so no kernel memory is modified and there is no write primitive.\nA:H - An excessively large wqe_size triggers a WARNING in the allocator (syzkaller-reported), which becomes a kernel panic under the common panic_on_warn hardening, causing denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/uverbs_cmd.c" ], "versions": [ { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7", "status": "affected", "versionType": "git" }, { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "9b5ac1c15334d46c0dbd49d64a2257b929500163", "status": "affected", "versionType": "git" }, { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "01c9b152647dc70dc06a4a2eff86ebb3b3c76075", "status": "affected", "versionType": "git" }, { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "bf1feed1a7886af945f92890493aefd2b5c9928a", "status": "affected", "versionType": "git" }, { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "d533425ac1f2925b4fc3e4ed9b9d72362cb23475", "status": "affected", "versionType": "git" }, { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "bf4454da8b1e712714628c0a0d6e7845bb40790a", "status": "affected", "versionType": "git" }, { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "bef70ff9841990658610512b4a18e4a88c9b4df6", "status": "affected", "versionType": "git" }, { "version": "c3bea3d2dc5358e05541527283279102383b0231", "lessThan": "1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/uverbs_cmd.c" ], "versions": [ { "version": "5.0", "status": "affected" }, { "version": "0", "lessThan": "5.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.252", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.202", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.165", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.128", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.75", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.14", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.4", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.10.252" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.15.202" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.1.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.6.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.12.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.18.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.19.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7" }, { "url": "https://git.kernel.org/stable/c/9b5ac1c15334d46c0dbd49d64a2257b929500163" }, { "url": "https://git.kernel.org/stable/c/01c9b152647dc70dc06a4a2eff86ebb3b3c76075" }, { "url": "https://git.kernel.org/stable/c/bf1feed1a7886af945f92890493aefd2b5c9928a" }, { "url": "https://git.kernel.org/stable/c/d533425ac1f2925b4fc3e4ed9b9d72362cb23475" }, { "url": "https://git.kernel.org/stable/c/bf4454da8b1e712714628c0a0d6e7845bb40790a" }, { "url": "https://git.kernel.org/stable/c/bef70ff9841990658610512b4a18e4a88c9b4df6" }, { "url": "https://git.kernel.org/stable/c/1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0" } ], "title": "RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-45856", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2026-10-16T15:18:02.441726Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:20:44.029Z" } } ] } }