scsi: megaraid_sas: return error when create DMA pool failed

JasonYanHw · martinkpetersen · commit bcf3b67d16a4 · 2019-02-19T18:58:38.000-05:00
when create DMA pool for cmd frames failed, we should return -ENOMEM,
instead of 0.
In some case in:

    megasas_init_adapter_fusion()

    --&gt;megasas_alloc_cmds()
       --&gt;megasas_create_frame_pool
          create DMA pool failed,
        --&gt; megasas_free_cmds() [1]

    --&gt;megasas_alloc_cmds_fusion()
       failed, then goto fail_alloc_cmds.
    --&gt;megasas_free_cmds() [2]

we will call megasas_free_cmds twice, [1] will kfree cmd_list,
[2] will use cmd_list.it will cause a problem:

Unable to handle kernel NULL pointer dereference at virtual address
00000000
pgd = ffffffc000f70000
[00000000] *pgd=0000001fbf893003, *pud=0000001fbf893003,
*pmd=0000001fbf894003, *pte=006000006d000707
Internal error: Oops: 96000005 [#1] SMP
 Modules linked in:
 CPU: 18 PID: 1 Comm: swapper/0 Not tainted
 task: ffffffdfb9290000 ti: ffffffdfb923c000 task.ti: ffffffdfb923c000
 PC is at megasas_free_cmds+0x30/0x70
 LR is at megasas_free_cmds+0x24/0x70
 ...
 Call trace:
 [&lt;ffffffc0005b779c&gt;] megasas_free_cmds+0x30/0x70
 [&lt;ffffffc0005bca74&gt;] megasas_init_adapter_fusion+0x2f4/0x4d8
 [&lt;ffffffc0005b926c&gt;] megasas_init_fw+0x2dc/0x760
 [&lt;ffffffc0005b9ab0&gt;] megasas_probe_one+0x3c0/0xcd8
 [&lt;ffffffc0004a5abc&gt;] local_pci_probe+0x4c/0xb4
 [&lt;ffffffc0004a5c40&gt;] pci_device_probe+0x11c/0x14c
 [&lt;ffffffc00053a5e4&gt;] driver_probe_device+0x1ec/0x430
 [&lt;ffffffc00053a92c&gt;] __driver_attach+0xa8/0xb0
 [&lt;ffffffc000538178&gt;] bus_for_each_dev+0x74/0xc8
  [&lt;ffffffc000539e88&gt;] driver_attach+0x28/0x34
 [&lt;ffffffc000539a18&gt;] bus_add_driver+0x16c/0x248
 [&lt;ffffffc00053b234&gt;] driver_register+0x6c/0x138
 [&lt;ffffffc0004a5350&gt;] __pci_register_driver+0x5c/0x6c
 [&lt;ffffffc000ce3868&gt;] megasas_init+0xc0/0x1a8
 [&lt;ffffffc000082a58&gt;] do_one_initcall+0xe8/0x1ec
 [&lt;ffffffc000ca7be8&gt;] kernel_init_freeable+0x1c8/0x284
 [&lt;ffffffc0008d90b8&gt;] kernel_init+0x1c/0xe4

Signed-off-by: Jason Yan &lt;yanaijie@huawei.com&gt;
Acked-by: Sumit Saxena &lt;sumit.saxena@broadcom.com&gt;
Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -4188,6 +4188,7 @@ int megasas_alloc_cmds(struct megasas_instance *instance)
 	if (megasas_create_frame_pool(instance)) {
 		dev_printk(KERN_DEBUG, &instance->pdev->dev, "Error creating frame DMA pool\n");
 		megasas_free_cmds(instance);
+		return -ENOMEM;
 	}
 
 	return 0;

Original file line number	Diff line number	Diff line change
`@@ -4188,6 +4188,7 @@ int megasas_alloc_cmds(struct megasas_instance *instance)`
`4188`	`4188`	`if (megasas_create_frame_pool(instance)) {`
`4189`	`4189`	`dev_printk(KERN_DEBUG, &instance->pdev->dev, "Error creating frame DMA pool\n");`
`4190`	`4190`	`megasas_free_cmds(instance);`
	`4191`	`+ return -ENOMEM;`
`4191`	`4192`	`}`
`4192`	`4193`
`4193`	`4194`	`return 0;`