CVE-2026-45973

RDMA/mlx5: Fix UMR hang in LAG error state unload

MEDIUM

5.5

CVSS Score

Published: May 27, 2026 at 12:18 PM UTC

Updated: October 21, 2026 at 01:19 PM UTC

1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

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

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

All versions6.11.11 ≤ v < 6.126.12.2 ≤ v < 6.12.756.13 ≤ v < 6.18.146.19 ≤ v < 6.19.46.6.64 ≤ v < 6.7542bd62b7a7f37182c9ef192c2bd25d118c144e46.11.11 6.12.2 6.13 6.6.646b0acf6a94c31efa43fce4edc22413a3390f9c05921fcf2971a1e8d3b904ba2c2905b96f4ec3d4adede132a5cf559f3ab35a4c28bac4f4a6c20334d8

Vendor states this is fixed in 613f5d4139b6ba801ccd93f9a28943be60d903bc (fixed)

Vendor states this is fixed in 6d838873da9cb97551d42316967cc82bf8f8031b (fixed)

Vendor states this is fixed in c8fb5c965ac7d0104872a8e4f6451f3bc6328199 (fixed)

Vendor states this is fixed in ebc2164a4cd4314503f1a0c8e7aaf76d7e5fa211 (fixed)

Affected range stops below 6.12, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 6.12.75 (unaffected)

Vendor states this is fixed in 6.13 (unaffected)

Vendor states this is fixed in 6.18.14 (unaffected)

Vendor states this is fixed in 6.19.4 (unaffected)

Vendor states this is fixed in 6.6.160 (unaffected)

Affected range stops below 6.7, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 7.0 (unaffected)