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 flushwork+0x19e/0x1b0 Workqueue: events smclgrterminatework [smc] RIP: 0010:flushwork+0x19e/0x1b0 Call Trace: ? _wakeupcommon+0x7a/0x190 ? workbusy+0x80/0x80 _cancelworktimer+0xe3/0x160 smcclosecancelwork+0x1a/0x70 [smc] smccloseactiveabort+0x207/0x360 [smc] _smclgrterminate.part.38+0xc8/0x180 [smc] processonework+0x19e/0x340 workerthread+0x30/0x370 ? processonework+0x340/0x340 kthread+0x117/0x130 ? _kthreadcancelwork+0x50/0x50 retfrom_fork+0x22/0x30
This is because when smcclosecancelwork is triggered, e.g. the RDMA driver is rmmod and the LGR is terminated, the conn->closework is flushed before initialization, resulting in WARN_ON(!work->func).
| smc_conn_create
| \- smc_lgr_register_conn
for conn in lgr->connsall | - smcconnkill | - smccloseactiveabort | - smcclosecancelwork | - cancelworksync | - _flushwork | (closework) | | smccloseinit | - INITWORK(&closework)
So fix this by initializing close_work before establishing the connection.