{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-45910", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.084Z", "datePublished": "2026-05-27T12:17:24.619Z", "dateUpdated": "2026-08-05T12:28:43.189Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:28:43.189Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix race condition in QP timer handlers\n\nI encontered the following warning:\n WARNING: drivers/infiniband/sw/rxe/rxe_task.c:249 at rxe_sched_task+0x1c8/0x238 [rdma_rxe], CPU#0: swapper/0/0\n...\n libsha1 [last unloaded: ip6_udp_tunnel]\n CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G C 6.19.0-rc5-64k-v8+ #37 PREEMPT\n Tainted: [C]=CRAP\n Hardware name: Raspberry Pi 4 Model B Rev 1.2\n Call trace:\n rxe_sched_task+0x1c8/0x238 [rdma_rxe] (P)\n retransmit_timer+0x130/0x188 [rdma_rxe]\n call_timer_fn+0x68/0x4d0\n __run_timers+0x630/0x888\n...\n WARNING: drivers/infiniband/sw/rxe/rxe_task.c:38 at rxe_sched_task+0x1c0/0x238 [rdma_rxe], CPU#0: swapper/0/0\n...\n WARNING: drivers/infiniband/sw/rxe/rxe_task.c:111 at do_work+0x488/0x5c8 [rdma_rxe], CPU#3: kworker/u17:4/93400\n...\n refcount_t: underflow; use-after-free.\n WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x138/0x1a0, CPU#3: kworker/u17:4/93400\n\nThe issue is caused by a race condition between retransmit_timer() and\nrxe_destroy_qp, leading to the Queue Pair's (QP) reference count dropping\nto zero during timer handler execution.\n\nIt seems this warning is harmless because rxe_qp_do_cleanup() will flush\nall pending timers and requests.\n\nExample of flow causing the issue:\n\nCPU0 CPU1\nretransmit_timer() {\n spin_lock_irqsave\n rxe_destroy_qp()\n __rxe_cleanup()\n __rxe_put() // qp->ref_count decrease to 0\n rxe_qp_do_cleanup() {\n if (qp->valid) {\n rxe_sched_task() {\n WARN_ON(rxe_read(task->qp) <= 0);\n }\n }\n spin_unlock_irqrestore\n}\n spin_lock_irqsave\n qp->valid = 0\n spin_unlock_irqrestore\n }\n\nEnsure the QP's reference count is maintained and its validity is checked\nwithin the timer callbacks by adding calls to rxe_get(qp) and corresponding\nrxe_put(qp) after use." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The race is between the local rxe_destroy_qp verb and a local QP timer firing, both driven through the RDMA uverbs interface; a remote peer cannot create or destroy QPs, so local access is required.\nAC:L - This is a race the attacker controls on both sides — creating a QP, driving RC traffic to arm the retransmit/rnr_nak timers, then destroying the QP — and it can be retried indefinitely across many QPs.\nPR:L - Triggering requires issuing RDMA verbs (create/destroy QP, post sends) via the uverbs device, which in RDMA deployments is routinely granted to non-root users (rdma group / container device access).\nUI:N - The attacker performs all QP creation, traffic, and destruction operations themselves with no victim action required.\nS:U - The use-after-free is contained within the kernel's own security authority with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - The refcount underflow / use-after-free on the QP object can give an attacker control over freed-object contents, enabling kernel memory disclosure.\nI:H - A use-after-free of the QP object enables heap grooming and arbitrary write primitives, per kernel UAF scoring guidance.\nA:H - The refcount underflow/use-after-free produces kernel warnings and can crash or panic the system when the freed QP is accessed." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/sw/rxe/rxe_comp.c", "drivers/infiniband/sw/rxe/rxe_req.c" ], "versions": [ { "version": "d94671632572813e90bcf475bb4c7d51fbf20173", "lessThan": "756c93d6df7c3bc599f6590b8e5afead6a41de1c", "status": "affected", "versionType": "git" }, { "version": "d94671632572813e90bcf475bb4c7d51fbf20173", "lessThan": "3c2ae79fb19dfd67341c14f1e78a5f1744eacfe2", "status": "affected", "versionType": "git" }, { "version": "d94671632572813e90bcf475bb4c7d51fbf20173", "lessThan": "5ae9da022ee3c97e6469eabcddce9271501ddbad", "status": "affected", "versionType": "git" }, { "version": "d94671632572813e90bcf475bb4c7d51fbf20173", "lessThan": "da379ca16af3722f159860d91a99cb6976a7500f", "status": "affected", "versionType": "git" }, { "version": "d94671632572813e90bcf475bb4c7d51fbf20173", "lessThan": "87bf646921430e303176edc4eb07c30160361b73", "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/sw/rxe/rxe_comp.c", "drivers/infiniband/sw/rxe/rxe_req.c" ], "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "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": "6.4", "versionEndExcluding": "6.6.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.18.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.19.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/756c93d6df7c3bc599f6590b8e5afead6a41de1c" }, { "url": "https://git.kernel.org/stable/c/3c2ae79fb19dfd67341c14f1e78a5f1744eacfe2" }, { "url": "https://git.kernel.org/stable/c/5ae9da022ee3c97e6469eabcddce9271501ddbad" }, { "url": "https://git.kernel.org/stable/c/da379ca16af3722f159860d91a99cb6976a7500f" }, { "url": "https://git.kernel.org/stable/c/87bf646921430e303176edc4eb07c30160361b73" } ], "title": "RDMA/rxe: Fix race condition in QP timer handlers", "x_generator": { "engine": "bippy-1.2.0" } } } }