CVE-2024-56641

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).

__smc_lgr_terminate | smc_connect_{rdma|ism}

-------------------------------------------------------------

| smc_conn_create

| \- smc_lgr_register_conn

for conn in lgr->conns_all |

\- smc_conn_kill |

\- smc_close_active_abort |

\- smc_close_cancel_work |

\- cancel_work_sync |

\- __flush_work |

(close_work) |

| smc_close_init

| \- INIT_WORK(&close_work)

So fix this by initializing close_work before establishing the

connection.