CVE-2024-56641

/// Technical description

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

net/smc: initialize close_work early to avoid warning

We encountered a warning that close_work was canceled before

initialization.

WARNING: CPU: 7 PID: 111103 at kernel/workqueue.c:3047 __flush_work+0x19e/0x1b0

Workqueue: events smc_lgr_terminate_work [smc]

RIP: 0010:__flush_work+0x19e/0x1b0

Call Trace:

? __wake_up_common+0x7a/0x190

? work_busy+0x80/0x80

__cancel_work_timer+0xe3/0x160

smc_close_cancel_work+0x1a/0x70 [smc]

smc_close_active_abort+0x207/0x360 [smc]

__smc_lgr_terminate.part.38+0xc8/0x180 [smc]

process_one_work+0x19e/0x340

worker_thread+0x30/0x370

? process_one_work+0x340/0x340

kthread+0x117/0x130

? __kthread_cancel_work+0x50/0x50

ret_from_fork+0x22/0x30

This is because when smc_close_cancel_work is triggered, e.g. the RDMA

driver is rmmod and the LGR is terminated, the conn->close_work is

flushed before initialization, resulting in WARN_ON(!work->func).

__sm

/// 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