CVE-2026-45973
Status: AnalyzedMedium (5.5)—
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.
Technical details traces, logs and code from the original report
[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
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Base score: 5.5
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.16%
- Percentile among all scored CVEs: 5
- Score date: 10/5/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
CWEs
- NVD-CWE-noinfo
References
Raw JSON (NVD)
Show
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/mlx5: Fix UMR hang in LAG error state unload\n\nDuring firmware reset in LAG mode, a race condition causes the driver\nto hang indefinitely while waiting for UMR completion during device\nunload. See [1].\n\nIn LAG mode the bond device is only registered on the master, so it\nnever sees sys_error events from the slave.\nDuring firmware reset this causes UMR waits to hang forever on unload\nas the slave is dead but the master hasn't entered error state yet, so\nUMR posts succeed but completions never arrive.\n\nFix this by adding a sys_error notifier that gets registered before\nMLX5_IB_STAGE_IB_REG and stays alive until after ib_unregister_device().\nThis ensures error events reach the bond device throughout teardown.\n\n[1]\nCall Trace:\n __schedule+0x2bd/0x760\n schedule+0x37/0xa0\n schedule_preempt_disabled+0xa/0x10\n __mutex_lock.isra.6+0x2b5/0x4a0\n __mlx5_ib_dereg_mr+0x606/0x870 [mlx5_ib]\n ? __xa_erase+0x4a/0xa0\n ? _cond_resched+0x15/0x30\n ? wait_for_completion+0x31/0x100\n ib_dereg_mr_user+0x48/0xc0 [ib_core]\n ? rdmacg_uncharge_hierarchy+0xa0/0x100\n destroy_hw_idr_uobject+0x20/0x50 [ib_uverbs]\n uverbs_destroy_uobject+0x37/0x150 [ib_uverbs]\n __uverbs_cleanup_ufile+0xda/0x140 [ib_uverbs]\n uverbs_destroy_ufile_hw+0x3a/0xf0 [ib_uverbs]\n ib_uverbs_remove_one+0xc3/0x140 [ib_uverbs]\n remove_client_context+0x8b/0xd0 [ib_core]\n disable_device+0x8c/0x130 [ib_core]\n __ib_unregister_device+0x10d/0x180 [ib_core]\n ib_unregister_device+0x21/0x30 [ib_core]\n __mlx5_ib_remove+0x1e4/0x1f0 [mlx5_ib]\n auxiliary_bus_remove+0x1e/0x30\n device_release_driver_internal+0x103/0x1f0\n bus_remove_device+0xf7/0x170\n device_del+0x181/0x410\n mlx5_rescan_drivers_locked.part.10+0xa9/0x1d0 [mlx5_core]\n mlx5_disable_lag+0x253/0x260 [mlx5_core]\n mlx5_lag_disable_change+0x89/0xc0 [mlx5_core]\n mlx5_eswitch_disable+0x67/0xa0 [mlx5_core]\n mlx5_unload+0x15/0xd0 [mlx5_core]\n mlx5_unload_one+0x71/0xc0 [mlx5_core]\n mlx5_sync_reset_reload_work+0x83/0x100 [mlx5_core]\n process_one_work+0x1a7/0x360\n worker_thread+0x30/0x390\n ? create_worker+0x1a0/0x1a0\n kthread+0x116/0x130\n ? kthread_flush_work_fn+0x10/0x10\n ret_from_fork+0x22/0x40"
}
],
"lastModified": "2026-06-17T10:52:49.597",
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