CVE-2021-47246

/// Technical description

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

net/mlx5e: Fix page reclaim for dead peer hairpin

When adding a hairpin flow, a firmware-side send queue is created for

the peer net device, which claims some host memory pages for its

internal ring buffer. If the peer net device is removed/unbound before

the hairpin flow is deleted, then the send queue is not destroyed which

leads to a stack trace on pci device remove:

[ 748.005230] mlx5_core 0000:08:00.2: wait_func:1094:(pid 12985): MANAGE_PAGES(0x108) timeout. Will cause a leak of a command resource

[ 748.005231] mlx5_core 0000:08:00.2: reclaim_pages:514:(pid 12985): failed reclaiming pages: err -110

[ 748.001835] mlx5_core 0000:08:00.2: mlx5_reclaim_root_pages:653:(pid 12985): failed reclaiming pages (-110) for func id 0x0

[ 748.002171] ------------[ cut here ]------------

[ 748.001177] FW pages counter is 4 after reclaiming all pages

[ 748.001186] WARNING: CPU: 1 PID: 12985 at drivers/net/ethernet/mellanox/mlx5

/// 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