From: Bart Van Assche bvanassche@acm.org
commit fc663711b94468f4e1427ebe289c9f05669699c9 upstream.
Remove the /proc/scsi/${proc_name} directory earlier to fix a race condition between unloading and reloading kernel modules. This fixes a bug introduced in 2009 by commit 77c019768f06 ("[SCSI] fix /proc memory leak in the SCSI core").
Fix the following kernel warning:
proc_dir_entry 'scsi/scsi_debug' already registered WARNING: CPU: 19 PID: 27986 at fs/proc/generic.c:376 proc_register+0x27d/0x2e0 Call Trace: proc_mkdir+0xb5/0xe0 scsi_proc_hostdir_add+0xb5/0x170 scsi_host_alloc+0x683/0x6c0 sdebug_driver_probe+0x6b/0x2d0 [scsi_debug] really_probe+0x159/0x540 __driver_probe_device+0xdc/0x230 driver_probe_device+0x4f/0x120 __device_attach_driver+0xef/0x180 bus_for_each_drv+0xe5/0x130 __device_attach+0x127/0x290 device_initial_probe+0x17/0x20 bus_probe_device+0x110/0x130 device_add+0x673/0xc80 device_register+0x1e/0x30 sdebug_add_host_helper+0x1a7/0x3b0 [scsi_debug] scsi_debug_init+0x64f/0x1000 [scsi_debug] do_one_initcall+0xd7/0x470 do_init_module+0xe7/0x330 load_module+0x122a/0x12c0 __do_sys_finit_module+0x124/0x1a0 __x64_sys_finit_module+0x46/0x50 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Link: https://lore.kernel.org/r/20230210205200.36973-3-bvanassche@acm.org Cc: Alan Stern stern@rowland.harvard.edu Cc: Yi Zhang yi.zhang@redhat.com Cc: stable@vger.kernel.org Fixes: 77c019768f06 ("[SCSI] fix /proc memory leak in the SCSI core") Reported-by: Yi Zhang yi.zhang@redhat.com Signed-off-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/hosts.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -181,6 +181,7 @@ void scsi_remove_host(struct Scsi_Host * scsi_forget_host(shost); mutex_unlock(&shost->scan_mutex); scsi_proc_host_rm(shost); + scsi_proc_hostdir_rm(shost->hostt);
/* * New SCSI devices cannot be attached anymore because of the SCSI host @@ -340,6 +341,7 @@ static void scsi_host_dev_release(struct struct Scsi_Host *shost = dev_to_shost(dev); struct device *parent = dev->parent;
+ /* In case scsi_remove_host() has not been called. */ scsi_proc_hostdir_rm(shost->hostt);
/* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */