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.

Affected Software

References

• https://git.kernel.org/stable/c/0541db8ee32c09463a72d0987382b3a3336b0043
• https://git.kernel.org/stable/c/6638e52dcfafaf1b9cbc34544f0c832db0069ea1
• https://git.kernel.org/stable/c/f0c37002210aaede10dae849d1a78efc2243add2