RDMA/mlx5: Fix UMR hang in LAG error state unload
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
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
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.6.64 to before 6.6.160; 6.12.2 to before 6.12.75; 6.1.191 to before 6.2; 6.11.11 to before 6.12 | 6.6.160, 6.12.75, 6.2, 6.12 | Patch available | CNA |
| Linux | Linux | 6.13 and later | 6.6.160, 6.12.75, 6.18.14, 6.19.4, 7.0 | Patch available | CNA |
- Linux VendorLinux Affected 6.6.64 to before 6.6.160; 6.12.2 to before 6.12.75; 6.1.191 to before 6.2; 6.11.11 to before 6.12 Fixed in 6.6.160, 6.12.75, 6.2, 6.12 Patch available CNA
- Linux VendorLinux Affected 6.13 and later Fixed in 6.6.160, 6.12.75, 6.18.14, 6.19.4, 7.0 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.6.64 to before 6.7; 6.11.11 to before 6.12; 6.12.2 to before 6.12.75; 6.13 to before 6.18.14; 6.19 to before 6.19.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.6.64 to before 6.7; 6.11.11 to before 6.12; 6.12.2 to before 6.12.75; 6.13 to before 6.18.14; 6.19 to before 6.19.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.160, 6.12.75, 6.2, 6.12
- Fix · CNA Linux (Linux) Fixed in 6.6.160, 6.12.75, 6.18.14, 6.19.4, 7.0
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 3 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-45973
- 2026-10-03 Alias added: GHSA-3hq7-v6j3-hpcm
- 2026-10-21 Fix available: Linux/Linux@33deba9bf5c34335182342588315f3db7dbc56d3, Linux/[email protected] · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-30 Fix available: Linux/[email protected] · CNA
- 2026-11-06 CISA SSVC decision points changed
References
Patch 4
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Sources
- CVE-2026-45973 · CVE Program
- CVE-2026-45973 · NVD
- FIRST EPSS
- GHSA-3hq7-v6j3-hpcm · GitHub Advisory Database · CC BY 4.0
- CVE-2026-45973 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences