Vulnerability-Lookup

GHSA-C82P-5M8Q-6JH9

Vulnerability from github – Published: 2026-09-17 18:31 – Updated: 2026-09-18 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

smb: smbdirect: free completion queues with ib_free_cq()

smbdirect_connection_destroy_qp() creates the send and receive completion queues with ib_alloc_cq_any(), which for IB_POLL_WORKQUEUE arms an internal completion handler that runs ib_cq_poll_work() on a workqueue. Tearing those CQs down with ib_destroy_cq() frees them without first cancelling that poll work.

If the provider posts a completion late -- for example Soft-RoCE (rxe) posting an RNR error from rxe_receiver() after rdma_destroy_qp() -- the handler re-queues ib_cq_poll_work() on the already-freed CQ, and a follow-on access faults in rxe_req_notify_cq().

Use ib_free_cq(), which cancel_work_sync()es the poll work before freeing the CQ, so no completion handler can run against a freed queue.

[ 1236.599526] ================================================================== [ 1236.602142] BUG: KASAN: slab-use-after-free in ib_cq_poll_work+0xd0/0x1a0 [ 1236.605524] Read of size 8 at addr ffff888111865800 by task kworker/4:1H/82 [ 1236.609017] [ 1236.609270] CPU: 4 UID: 0 PID: 82 Comm: kworker/4:1H Not tainted 7.2.0-rc3-next-20260717-virtme #110 PREEMPT(lazy) [ 1236.609287] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 [ 1236.609498] Workqueue: ib-comp-wq ib_cq_poll_work [ 1236.609525] Call Trace: [ 1236.609536] [ 1236.609545] __dump_stack+0x21/0x60 [ 1236.609562] dump_stack_lvl+0xc2/0x100 [ 1236.609573] print_address_description+0x77/0x200 [ 1236.609587] ? ib_cq_poll_work+0xd0/0x1a0 [ 1236.609597] print_report+0x58/0x70 [ 1236.609607] kasan_report+0x117/0x150 [ 1236.609623] ? ib_cq_poll_work+0xd0/0x1a0 [ 1236.609636] ? process_scheduled_works+0x954/0x1600 [ 1236.609650] ib_cq_poll_work+0xd0/0x1a0 [ 1236.609662] ? process_scheduled_works+0x954/0x1600 [ 1236.609674] process_scheduled_works+0xc22/0x1600 [ 1236.609698] ? __pfx_process_scheduled_works+0x10/0x10 [ 1236.609713] ? __pfx_assign_work+0x10/0x10 [ 1236.609726] ? lock_is_held_type+0x7b/0x110 [ 1236.609741] worker_thread+0x975/0xee0 [ 1236.609757] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 1236.609775] ? __kthread_parkme+0x21e/0x260 [ 1236.609789] kthread+0x3a6/0x490 [ 1236.609800] ? __pfx_worker_thread+0x10/0x10 [ 1236.609809] ? __pfx_kthread+0x10/0x10 [ 1236.609820] ret_from_fork+0x55a/0xa20 [ 1236.609835] ? __pfx_ret_from_fork+0x10/0x10 [ 1236.609850] ? __pfx_kthread+0x10/0x10 [ 1236.609861] ret_from_fork_asm+0x1a/0x30 [ 1236.609880] [ 1236.609886] [ 1236.661292] Allocated by task 5076: [ 1236.662640] kasan_save_track+0x3e/0x80 [ 1236.663842] __kasan_kmalloc+0x72/0x90 [ 1236.664763] __kmalloc_noprof+0x2b0/0x5d0 [ 1236.665356] __ib_alloc_cq+0x284/0x1000 [ 1236.666573] __ib_alloc_cq_any+0x23e/0x340 [ 1236.668654] smbdirect_connection_create_qp+0x6f7/0x1070 [ 1236.669757] smbdirect_accept_connect_request+0x500/0x1ca0 [ 1236.672625] smbdirect_listen_rdma_event_handler+0x1655/0x1c50 [ 1236.673930] cma_listen_handler+0x1bf/0x260 [ 1236.674923] cma_cm_event_handler+0x128/0x380 [ 1236.676926] cma_ib_req_handler+0x2d3d/0x4de0 [ 1236.678368] cm_process_work+0xb0/0x530 [ 1236.680454] cm_queue_work_unlock+0xb1/0x230 [ 1236.681673] cm_work_handler+0x969f/0xdca0 [ 1236.682704] process_scheduled_works+0xc22/0x1600 [ 1236.683447] worker_thread+0x975/0xee0 [ 1236.685901] kthread+0x3a6/0x490 [ 1236.688164] ret_from_fork+0x55a/0xa20 [ 1236.689522] ret_from_fork_asm+0x1a/0x30 [ 1236.690073] [ 1236.690378] Freed by task 5137: [ 1236.692242] kasan_save_track+0x3e/0x80 [ 1236.694272] kasan_save_free_info+0x40/0x50 [ 1236.695514] __kasan_slab_free+0x3a/0x60 [ 1236.696773] kfree+0x14e/0x4e0 [ 1236.697216] ib_destroy_cq_user+0x18d/0x250 [ 1236.699817] smbdirect_connection_destroy_qp+0xf2/0x280 [ 1236.702115] smbdirect_socket_destroy_sync+0x1607/0x2720 [ 1236.704062] smbdirect_socket_release+0x140/0x280 [ 1236.705286] smb_direct_free_transpor ---truncated---

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-90173"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-17T17:17:10Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: smbdirect: free completion queues with ib_free_cq()\n\nsmbdirect_connection_destroy_qp() creates the send and receive completion\nqueues with ib_alloc_cq_any(), which for IB_POLL_WORKQUEUE arms an\ninternal completion handler that runs ib_cq_poll_work() on a workqueue.\nTearing those CQs down with ib_destroy_cq() frees them without first\ncancelling that poll work.\n\nIf the provider posts a completion late -- for example Soft-RoCE (rxe)\nposting an RNR error from rxe_receiver() after rdma_destroy_qp() -- the\nhandler re-queues ib_cq_poll_work() on the already-freed CQ, and a\nfollow-on access faults in rxe_req_notify_cq().\n\nUse ib_free_cq(), which cancel_work_sync()es the poll work before freeing\nthe CQ, so no completion handler can run against a freed queue.\n\n[ 1236.599526] ==================================================================\n[ 1236.602142] BUG: KASAN: slab-use-after-free in ib_cq_poll_work+0xd0/0x1a0\n[ 1236.605524] Read of size 8 at addr ffff888111865800 by task kworker/4:1H/82\n[ 1236.609017]\n[ 1236.609270] CPU: 4 UID: 0 PID: 82 Comm: kworker/4:1H Not tainted 7.2.0-rc3-next-20260717-virtme #110 PREEMPT(lazy)\n[ 1236.609287] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\n[ 1236.609498] Workqueue: ib-comp-wq ib_cq_poll_work\n[ 1236.609525] Call Trace:\n[ 1236.609536]  \u003cTASK\u003e\n[ 1236.609545]  __dump_stack+0x21/0x60\n[ 1236.609562]  dump_stack_lvl+0xc2/0x100\n[ 1236.609573]  print_address_description+0x77/0x200\n[ 1236.609587]  ? ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609597]  print_report+0x58/0x70\n[ 1236.609607]  kasan_report+0x117/0x150\n[ 1236.609623]  ? ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609636]  ? process_scheduled_works+0x954/0x1600\n[ 1236.609650]  ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609662]  ? process_scheduled_works+0x954/0x1600\n[ 1236.609674]  process_scheduled_works+0xc22/0x1600\n[ 1236.609698]  ? __pfx_process_scheduled_works+0x10/0x10\n[ 1236.609713]  ? __pfx_assign_work+0x10/0x10\n[ 1236.609726]  ? lock_is_held_type+0x7b/0x110\n[ 1236.609741]  worker_thread+0x975/0xee0\n[ 1236.609757]  ? __pfx_do_raw_spin_lock+0x10/0x10\n[ 1236.609775]  ? __kthread_parkme+0x21e/0x260\n[ 1236.609789]  kthread+0x3a6/0x490\n[ 1236.609800]  ? __pfx_worker_thread+0x10/0x10\n[ 1236.609809]  ? __pfx_kthread+0x10/0x10\n[ 1236.609820]  ret_from_fork+0x55a/0xa20\n[ 1236.609835]  ? __pfx_ret_from_fork+0x10/0x10\n[ 1236.609850]  ? __pfx_kthread+0x10/0x10\n[ 1236.609861]  ret_from_fork_asm+0x1a/0x30\n[ 1236.609880]  \u003c/TASK\u003e\n[ 1236.609886]\n[ 1236.661292] Allocated by task 5076:\n[ 1236.662640]  kasan_save_track+0x3e/0x80\n[ 1236.663842]  __kasan_kmalloc+0x72/0x90\n[ 1236.664763]  __kmalloc_noprof+0x2b0/0x5d0\n[ 1236.665356]  __ib_alloc_cq+0x284/0x1000\n[ 1236.666573]  __ib_alloc_cq_any+0x23e/0x340\n[ 1236.668654]  smbdirect_connection_create_qp+0x6f7/0x1070\n[ 1236.669757]  smbdirect_accept_connect_request+0x500/0x1ca0\n[ 1236.672625]  smbdirect_listen_rdma_event_handler+0x1655/0x1c50\n[ 1236.673930]  cma_listen_handler+0x1bf/0x260\n[ 1236.674923]  cma_cm_event_handler+0x128/0x380\n[ 1236.676926]  cma_ib_req_handler+0x2d3d/0x4de0\n[ 1236.678368]  cm_process_work+0xb0/0x530\n[ 1236.680454]  cm_queue_work_unlock+0xb1/0x230\n[ 1236.681673]  cm_work_handler+0x969f/0xdca0\n[ 1236.682704]  process_scheduled_works+0xc22/0x1600\n[ 1236.683447]  worker_thread+0x975/0xee0\n[ 1236.685901]  kthread+0x3a6/0x490\n[ 1236.688164]  ret_from_fork+0x55a/0xa20\n[ 1236.689522]  ret_from_fork_asm+0x1a/0x30\n[ 1236.690073]\n[ 1236.690378] Freed by task 5137:\n[ 1236.692242]  kasan_save_track+0x3e/0x80\n[ 1236.694272]  kasan_save_free_info+0x40/0x50\n[ 1236.695514]  __kasan_slab_free+0x3a/0x60\n[ 1236.696773]  kfree+0x14e/0x4e0\n[ 1236.697216]  ib_destroy_cq_user+0x18d/0x250\n[ 1236.699817]  smbdirect_connection_destroy_qp+0xf2/0x280\n[ 1236.702115]  smbdirect_socket_destroy_sync+0x1607/0x2720\n[ 1236.704062]  smbdirect_socket_release+0x140/0x280\n[ 1236.705286]  smb_direct_free_transpor\n---truncated---",
  "id": "GHSA-c82p-5m8q-6jh9",
  "modified": "2026-09-18T18:31:27Z",
  "published": "2026-09-17T18:31:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90173"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8a953b1a47fffb71e70767bc1e914401e3c2f27f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fe2c0cacbcff9d56c03b296f68f22151c4223b04"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-90173 (GCVE-0-2026-90173)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:07 – Updated: 2026-09-18 17:53

Title

smb: smbdirect: free completion queues with ib_free_cq()

Summary

In the Linux kernel, the following vulnerability has been resolved: smb: smbdirect: free completion queues with ib_free_cq() smbdirect_connection_destroy_qp() creates the send and receive completion queues with ib_alloc_cq_any(), which for IB_POLL_WORKQUEUE arms an internal completion handler that runs ib_cq_poll_work() on a workqueue. Tearing those CQs down with ib_destroy_cq() frees them without first cancelling that poll work. If the provider posts a completion late -- for example Soft-RoCE (rxe) posting an RNR error from rxe_receiver() after rdma_destroy_qp() -- the handler re-queues ib_cq_poll_work() on the already-freed CQ, and a follow-on access faults in rxe_req_notify_cq(). Use ib_free_cq(), which cancel_work_sync()es the poll work before freeing the CQ, so no completion handler can run against a freed queue. [ 1236.599526] ================================================================== [ 1236.602142] BUG: KASAN: slab-use-after-free in ib_cq_poll_work+0xd0/0x1a0 [ 1236.605524] Read of size 8 at addr ffff888111865800 by task kworker/4:1H/82 [ 1236.609017] [ 1236.609270] CPU: 4 UID: 0 PID: 82 Comm: kworker/4:1H Not tainted 7.2.0-rc3-next-20260717-virtme #110 PREEMPT(lazy) [ 1236.609287] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 [ 1236.609498] Workqueue: ib-comp-wq ib_cq_poll_work [ 1236.609525] Call Trace: [ 1236.609536] <TASK> [ 1236.609545] __dump_stack+0x21/0x60 [ 1236.609562] dump_stack_lvl+0xc2/0x100 [ 1236.609573] print_address_description+0x77/0x200 [ 1236.609587] ? ib_cq_poll_work+0xd0/0x1a0 [ 1236.609597] print_report+0x58/0x70 [ 1236.609607] kasan_report+0x117/0x150 [ 1236.609623] ? ib_cq_poll_work+0xd0/0x1a0 [ 1236.609636] ? process_scheduled_works+0x954/0x1600 [ 1236.609650] ib_cq_poll_work+0xd0/0x1a0 [ 1236.609662] ? process_scheduled_works+0x954/0x1600 [ 1236.609674] process_scheduled_works+0xc22/0x1600 [ 1236.609698] ? __pfx_process_scheduled_works+0x10/0x10 [ 1236.609713] ? __pfx_assign_work+0x10/0x10 [ 1236.609726] ? lock_is_held_type+0x7b/0x110 [ 1236.609741] worker_thread+0x975/0xee0 [ 1236.609757] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 1236.609775] ? __kthread_parkme+0x21e/0x260 [ 1236.609789] kthread+0x3a6/0x490 [ 1236.609800] ? __pfx_worker_thread+0x10/0x10 [ 1236.609809] ? __pfx_kthread+0x10/0x10 [ 1236.609820] ret_from_fork+0x55a/0xa20 [ 1236.609835] ? __pfx_ret_from_fork+0x10/0x10 [ 1236.609850] ? __pfx_kthread+0x10/0x10 [ 1236.609861] ret_from_fork_asm+0x1a/0x30 [ 1236.609880] </TASK> [ 1236.609886] [ 1236.661292] Allocated by task 5076: [ 1236.662640] kasan_save_track+0x3e/0x80 [ 1236.663842] __kasan_kmalloc+0x72/0x90 [ 1236.664763] __kmalloc_noprof+0x2b0/0x5d0 [ 1236.665356] __ib_alloc_cq+0x284/0x1000 [ 1236.666573] __ib_alloc_cq_any+0x23e/0x340 [ 1236.668654] smbdirect_connection_create_qp+0x6f7/0x1070 [ 1236.669757] smbdirect_accept_connect_request+0x500/0x1ca0 [ 1236.672625] smbdirect_listen_rdma_event_handler+0x1655/0x1c50 [ 1236.673930] cma_listen_handler+0x1bf/0x260 [ 1236.674923] cma_cm_event_handler+0x128/0x380 [ 1236.676926] cma_ib_req_handler+0x2d3d/0x4de0 [ 1236.678368] cm_process_work+0xb0/0x530 [ 1236.680454] cm_queue_work_unlock+0xb1/0x230 [ 1236.681673] cm_work_handler+0x969f/0xdca0 [ 1236.682704] process_scheduled_works+0xc22/0x1600 [ 1236.683447] worker_thread+0x975/0xee0 [ 1236.685901] kthread+0x3a6/0x490 [ 1236.688164] ret_from_fork+0x55a/0xa20 [ 1236.689522] ret_from_fork_asm+0x1a/0x30 [ 1236.690073] [ 1236.690378] Freed by task 5137: [ 1236.692242] kasan_save_track+0x3e/0x80 [ 1236.694272] kasan_save_free_info+0x40/0x50 [ 1236.695514] __kasan_slab_free+0x3a/0x60 [ 1236.696773] kfree+0x14e/0x4e0 [ 1236.697216] ib_destroy_cq_user+0x18d/0x250 [ 1236.699817] smbdirect_connection_destroy_qp+0xf2/0x280 [ 1236.702115] smbdirect_socket_destroy_sync+0x1607/0x2720 [ 1236.704062] smbdirect_socket_release+0x140/0x280 [ 1236.705286] smb_direct_free_transpor ---truncated---

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/8a953b1a47fffb71e…
https://git.kernel.org/stable/c/fe2c0cacbcff9d56c…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 6073eb3e31756d569c4853fb22724525739d0e0c , < 8a953b1a47fffb71e70767bc1e914401e3c2f27f (git) Affected: 6073eb3e31756d569c4853fb22724525739d0e0c , < fe2c0cacbcff9d56c03b296f68f22151c4223b04 (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/smbdirect/connection.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "8a953b1a47fffb71e70767bc1e914401e3c2f27f",
              "status": "affected",
              "version": "6073eb3e31756d569c4853fb22724525739d0e0c",
              "versionType": "git"
            },
            {
              "lessThan": "fe2c0cacbcff9d56c03b296f68f22151c4223b04",
              "status": "affected",
              "version": "6073eb3e31756d569c4853fb22724525739d0e0c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/smbdirect/connection.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: smbdirect: free completion queues with ib_free_cq()\n\nsmbdirect_connection_destroy_qp() creates the send and receive completion\nqueues with ib_alloc_cq_any(), which for IB_POLL_WORKQUEUE arms an\ninternal completion handler that runs ib_cq_poll_work() on a workqueue.\nTearing those CQs down with ib_destroy_cq() frees them without first\ncancelling that poll work.\n\nIf the provider posts a completion late -- for example Soft-RoCE (rxe)\nposting an RNR error from rxe_receiver() after rdma_destroy_qp() -- the\nhandler re-queues ib_cq_poll_work() on the already-freed CQ, and a\nfollow-on access faults in rxe_req_notify_cq().\n\nUse ib_free_cq(), which cancel_work_sync()es the poll work before freeing\nthe CQ, so no completion handler can run against a freed queue.\n\n[ 1236.599526] ==================================================================\n[ 1236.602142] BUG: KASAN: slab-use-after-free in ib_cq_poll_work+0xd0/0x1a0\n[ 1236.605524] Read of size 8 at addr ffff888111865800 by task kworker/4:1H/82\n[ 1236.609017]\n[ 1236.609270] CPU: 4 UID: 0 PID: 82 Comm: kworker/4:1H Not tainted 7.2.0-rc3-next-20260717-virtme #110 PREEMPT(lazy)\n[ 1236.609287] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\n[ 1236.609498] Workqueue: ib-comp-wq ib_cq_poll_work\n[ 1236.609525] Call Trace:\n[ 1236.609536]  \u003cTASK\u003e\n[ 1236.609545]  __dump_stack+0x21/0x60\n[ 1236.609562]  dump_stack_lvl+0xc2/0x100\n[ 1236.609573]  print_address_description+0x77/0x200\n[ 1236.609587]  ? ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609597]  print_report+0x58/0x70\n[ 1236.609607]  kasan_report+0x117/0x150\n[ 1236.609623]  ? ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609636]  ? process_scheduled_works+0x954/0x1600\n[ 1236.609650]  ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609662]  ? process_scheduled_works+0x954/0x1600\n[ 1236.609674]  process_scheduled_works+0xc22/0x1600\n[ 1236.609698]  ? __pfx_process_scheduled_works+0x10/0x10\n[ 1236.609713]  ? __pfx_assign_work+0x10/0x10\n[ 1236.609726]  ? lock_is_held_type+0x7b/0x110\n[ 1236.609741]  worker_thread+0x975/0xee0\n[ 1236.609757]  ? __pfx_do_raw_spin_lock+0x10/0x10\n[ 1236.609775]  ? __kthread_parkme+0x21e/0x260\n[ 1236.609789]  kthread+0x3a6/0x490\n[ 1236.609800]  ? __pfx_worker_thread+0x10/0x10\n[ 1236.609809]  ? __pfx_kthread+0x10/0x10\n[ 1236.609820]  ret_from_fork+0x55a/0xa20\n[ 1236.609835]  ? __pfx_ret_from_fork+0x10/0x10\n[ 1236.609850]  ? __pfx_kthread+0x10/0x10\n[ 1236.609861]  ret_from_fork_asm+0x1a/0x30\n[ 1236.609880]  \u003c/TASK\u003e\n[ 1236.609886]\n[ 1236.661292] Allocated by task 5076:\n[ 1236.662640]  kasan_save_track+0x3e/0x80\n[ 1236.663842]  __kasan_kmalloc+0x72/0x90\n[ 1236.664763]  __kmalloc_noprof+0x2b0/0x5d0\n[ 1236.665356]  __ib_alloc_cq+0x284/0x1000\n[ 1236.666573]  __ib_alloc_cq_any+0x23e/0x340\n[ 1236.668654]  smbdirect_connection_create_qp+0x6f7/0x1070\n[ 1236.669757]  smbdirect_accept_connect_request+0x500/0x1ca0\n[ 1236.672625]  smbdirect_listen_rdma_event_handler+0x1655/0x1c50\n[ 1236.673930]  cma_listen_handler+0x1bf/0x260\n[ 1236.674923]  cma_cm_event_handler+0x128/0x380\n[ 1236.676926]  cma_ib_req_handler+0x2d3d/0x4de0\n[ 1236.678368]  cm_process_work+0xb0/0x530\n[ 1236.680454]  cm_queue_work_unlock+0xb1/0x230\n[ 1236.681673]  cm_work_handler+0x969f/0xdca0\n[ 1236.682704]  process_scheduled_works+0xc22/0x1600\n[ 1236.683447]  worker_thread+0x975/0xee0\n[ 1236.685901]  kthread+0x3a6/0x490\n[ 1236.688164]  ret_from_fork+0x55a/0xa20\n[ 1236.689522]  ret_from_fork_asm+0x1a/0x30\n[ 1236.690073]\n[ 1236.690378] Freed by task 5137:\n[ 1236.692242]  kasan_save_track+0x3e/0x80\n[ 1236.694272]  kasan_save_free_info+0x40/0x50\n[ 1236.695514]  __kasan_slab_free+0x3a/0x60\n[ 1236.696773]  kfree+0x14e/0x4e0\n[ 1236.697216]  ib_destroy_cq_user+0x18d/0x250\n[ 1236.699817]  smbdirect_connection_destroy_qp+0xf2/0x280\n[ 1236.702115]  smbdirect_socket_destroy_sync+0x1607/0x2720\n[ 1236.704062]  smbdirect_socket_release+0x140/0x280\n[ 1236.705286]  smb_direct_free_transpor\n---truncated---"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - A remote InfiniBand CM CONNECT_REQUEST handled by smbdirect_listen_rdma_event_handler() reaches smbdirect_accept_connect_request(), which allocates the CQs; the same peer\u0027s later RDMA packets make rxe_receiver() post a completion after rdma_destroy_qp(), use-after-freeing them. ksmbd listens for this on RoCE/IB port 445 and iWARP port 5445.\nAC:L - The attacker controls both sides: they send the CONNECT_REQUEST that creates the CQs in smbdirect_connection_create_qp(), then disconnect or keep sending RDMA packets so rxe_receiver() queues ib_cq_poll_work() while smbdirect_connection_destroy_qp() frees the CQ with ib_destroy_cq() instead of ib_free_cq(), skipping cancel_work_sync().\nPR:N - CQ allocation runs in smbdirect_accept_connect_request() on the unauthenticated RDMA CM CONNECT_REQUEST path, before SMB Direct negotiate completes and before any SMB2 SESSION_SETUP. Connection teardown through __ksmbd_conn_release_work() likewise needs no credentials.\nUI:N - The attacker alone sends the RDMA CM CONNECT_REQUEST to the ksmbd listener started by smb_direct_listen() and later drops that connection so ksmbd_conn_handler_loop() calls smbdirect_connection_destroy_qp(); no local user mount, click, or prompt is required.\nS:U - The use-after-free is of the kernel struct ib_cq allocated by __ib_alloc_cq() and later touched by ib_cq_poll_work() on the same host; it does not cross a VM, IOMMU, or sandbox boundary.\nC:H - ib_cq_poll_work() reads a kmalloc-freed struct ib_cq (cq-\u003ewc and cq-\u003edevice) after ib_destroy_cq_user(); reclaiming that slab object lets the attacker supply a fake ib_device and obtain a kernel read primitive through the poll/notify path.\nI:H - The same reclaimed ib_cq is used as cq-\u003edevice-\u003eops.poll_cq and req_notify_cq from ib_cq_poll_work(), so a sprayed fake ops table yields a kernel function-pointer hijack, not merely a crash.\nA:H - The demonstrated KASAN use-after-free in ib_cq_poll_work() and the follow-on oops in rxe_req_notify_cq() crash the kernel; a remote peer can repeat connect-and-teardown against the ksmbd SMB Direct listener."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T17:53:33.402Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/8a953b1a47fffb71e70767bc1e914401e3c2f27f"
        },
        {
          "url": "https://git.kernel.org/stable/c/fe2c0cacbcff9d56c03b296f68f22151c4223b04"
        }
      ],
      "title": "smb: smbdirect: free completion queues with ib_free_cq()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90173",
    "datePublished": "2026-09-17T16:07:00.463Z",
    "dateReserved": "2026-09-11T19:38:34.791Z",
    "dateUpdated": "2026-09-18T17:53:33.402Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
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Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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