{"id":"CVE-2026-45910","title":"RDMA/rxe: Fix race condition in QP timer handlers","summary":"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 …","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 756c93d6df7c3bc599f6590b8e5afead6a41de1c","Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 3c2ae79fb19dfd67341c14f1e78a5f1744eacfe2","Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 5ae9da022ee3c97e6469eabcddce9271501ddbad","Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < da379ca16af3722f159860d91a99cb6976a7500f","Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 87bf646921430e303176edc4eb07c30160361b73","Linux 6.4"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:18:23.890449Z"},"published":"2026-05-27","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:46.695Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-45910","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"}],"tags":["cve.org"],"epss":0.00102,"epssPercentile":0.00889,"ingestedAt":"2026-10-16T17:24:46.700Z","slug":"CVE-2026-45910","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 756c93d6df7c3bc599f6590b8e5afead6a41de1c`\n- `Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 3c2ae79fb19dfd67341c14f1e78a5f1744eacfe2`\n- `Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 5ae9da022ee3c97e6469eabcddce9271501ddbad`\n- `Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < da379ca16af3722f159860d91a99cb6976a7500f`\n- `Linux >= d94671632572813e90bcf475bb4c7d51fbf20173 < 87bf646921430e303176edc4eb07c30160361b73`\n- `Linux 6.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}