CVE-2025-38373

/// Technical description

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

IB/mlx5: Fix potential deadlock in MR deregistration

The issue arises when kzalloc() is invoked while holding umem_mutex or

any other lock acquired under umem_mutex. This is problematic because

kzalloc() can trigger fs_reclaim_aqcuire(), which may, in turn, invoke

mmu_notifier_invalidate_range_start(). This function can lead to

mlx5_ib_invalidate_range(), which attempts to acquire umem_mutex again,

resulting in a deadlock.

The problematic flow:

CPU0 | CPU1

---------------------------------------|------------------------------------------------

mlx5_ib_dereg_mr() |

→ revoke_mr() |

→ mutex_lock(&umem_odp->umem_mutex) |

| mlx5_mkey_cache_init()

| → mutex_lock(&dev->cache.rb_lock)

| → mlx5r_cache_create_ent_lo

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References