CVE-2024-50095

/// Technical description

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

RDMA/mad: Improve handling of timed out WRs of mad agent

Current timeout handler of mad agent acquires/releases mad_agent_priv

lock for every timed out WRs. This causes heavy locking contention

when higher no. of WRs are to be handled inside timeout handler.

This leads to softlockup with below trace in some use cases where

rdma-cm path is used to establish connection between peer nodes

Trace:

-----

BUG: soft lockup - CPU#4 stuck for 26s! [kworker/u128:3:19767]

CPU: 4 PID: 19767 Comm: kworker/u128:3 Kdump: loaded Tainted: G OE

------- --- 5.14.0-427.13.1.el9_4.x86_64 #1

Hardware name: Dell Inc. PowerEdge R740/01YM03, BIOS 2.4.8 11/26/2019

Workqueue: ib_mad1 timeout_sends [ib_core]

RIP: 0010:__do_softirq+0x78/0x2ac

RSP: 0018:ffffb253449e4f98 EFLAGS: 00000246

RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 000000000000001f

RDX: 000000000000001d RSI: 000000003d1879ab RDI: fff363b66fd3a86b

RBP: ffffb253

/// 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