CVE-2026-45973RDMA/mlx5: Fix UMR hang in LAG error state unload

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix UMR hang in LAG error state unload During firmware reset in LAG mode, a race condition causes the driver to hang indefinitely while waiting for UMR completion during device unload. See [1]. In LAG mode the bond device is only registered on the master, so it never sees sys_error events from the slave. During firmware reset this causes UMR waits to hang forever on unload as the slave is dead but the master hasn't entered error state yet, so UMR posts succeed but completions never arrive. Fix this by adding a sys_error notifier that gets registered before MLX5_IB_STAGE_IB_REG and stays alive until after ib_unregister_device(). This ensures error events reach the bond device throughout teardown. [1] Call Trace: __schedule+0x2bd/0x760 schedule+0x37/0xa0 schedule_preempt_disabled+0xa/0x10 __mutex_lock.isra.6+0x2b5/0x4a0 __mlx5_ib_dereg_mr+0x606/0x870 [mlx5_ib] ? __xa_erase+0x4a/0xa0 ? _cond_resched+0x15/0x30 ? wait_for_completion+0x31/0x100 ib_dereg_mr_user+0x48/0xc0 [ib_core] ? rdmacg_uncharge_hierarchy+0xa0/0x100 destroy_hw_idr_uobject+0x20/0x50 [ib_uverbs] uverbs_destroy_uobject+0x37/0x150 [ib_uverbs] __uverbs_cleanup_ufile+0xda/0x140 [ib_uverbs] uverbs_destroy_ufile_hw+0x3a/0xf0 [ib_uverbs] ib_uverbs_remove_one+0xc3/0x140 [ib_uverbs] remove_client_context+0x8b/0xd0 [ib_core] disable_device+0x8c/0x130 [ib_core] __ib_unregister_device+0x10d/0x180 [ib_core] ib_unregister_device+0x21/0x30 [ib_core] __mlx5_ib_remove+0x1e4/0x1f0 [mlx5_ib] auxiliary_bus_remove+0x1e/0x30 device_release_driver_internal+0x103/0x1f0 bus_remove_device+0xf7/0x170 device_del+0x181/0x410 mlx5_rescan_drivers_locked.part.10+0xa9/0x1d0 [mlx5_core] mlx5_disable_lag+0x253/0x260 [mlx5_core] mlx5_lag_disable_change+0x89/0xc0 [mlx5_core] mlx5_eswitch_disable+0x67/0xa0 [mlx5_core] mlx5_unload+0x15/0xd0 [mlx5_core] mlx5_unload_one+0x71/0xc0 [mlx5_core] mlx5_sync_reset_reload_work+0x83/0x100 [mlx5_core] process_one_work+0x1a7/0x360 worker_thread+0x30/0x390 ? create_worker+0x1a0/0x1a0 kthread+0x116/0x130 ? kthread_flush_work_fn+0x10/0x10 ret_from_fork+0x22/0x40

Timeline

Scores

EPSS (exploitation in 30 days)

0.16% · top 95% of all CVEs (12 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Affected products

• Linux · Linux

  • affected 921fcf2971a1e8d3b904ba2c2905b96f4ec3d4ad – < 33deba9bf5c34335182342588315f3db7dbc56d3
  • affected 6b0acf6a94c31efa43fce4edc22413a3390f9c05 – < c8fb5c965ac7d0104872a8e4f6451f3bc6328199
  • affected ede132a5cf559f3ab35a4c28bac4f4a6c20334d8 – < 6d838873da9cb97551d42316967cc82bf8f8031b
  • affected ede132a5cf559f3ab35a4c28bac4f4a6c20334d8 – < 613f5d4139b6ba801ccd93f9a28943be60d903bc
  • affected ede132a5cf559f3ab35a4c28bac4f4a6c20334d8 – < ebc2164a4cd4314503f1a0c8e7aaf76d7e5fa211
  • affected 09ef1c03a7ac2b57be8aeb0c7a75d538ded2562a
  • affected 542bd62b7a7f37182c9ef192c2bd25d118c144e4
  • affected 6.6.64 – < 6.6.160
  • affected 6.12.2 – < 6.12.75
  • affected 6.1.191 – < 6.2
  • affected 6.11.11 – < 6.12

• Linux · Linux

  • affected 6.13
  • unaffected < 6.13
  • unaffected 6.6.160 – ≤ 6.6.*
  • unaffected 6.12.75 – ≤ 6.12.*
  • unaffected 6.18.14 – ≤ 6.18.*
  • unaffected 6.19.4 – ≤ 6.19.*
  • unaffected 7.0 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-32257 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-45973](https://cveledger.app/badge/CVE-2026-45973.svg)](https://cveledger.app/cve/CVE-2026-45973)

Record last updated 6 Nov 2026, 16:13 UTC.