[PATCH] scsi: megaraid_sas: fix memleak in megasas_alloc_cmdlist_fusion

[shuwang]

From: Shu Wang <shuwang@xxxxxxxxxx>

Found this issue by kmemleak, a few kb mem was leaked in
megasas_alloc_cmdlist_fusion when kzalloc failed for one
megasas_cmd_fusion allocation.

unreferenced object 0xffff88045dbd2000 (size 8192):
  comm "systemd-udevd", pid 323, jiffies 4294671759 (age 49.008s)
  backtrace:
    [<ffffffff8176166a>] kmemleak_alloc+0x4a/0xa0
    [<ffffffff812186a8>] __kmalloc+0xe8/0x220
    [<ffffffffc0060594>] megasas_alloc_cmdlist_fusion+0x34/0xe0 [megaraid_sas]
(gdb) list *megasas_alloc_cmdlist_fusion+0x34
0xd5c4 is in megasas_alloc_cmdlist_fusion
               (drivers/scsi/megaraid/megaraid_sas_fusion.c:443).
    [<ffffffffc0060ca5>] megasas_alloc_cmds_fusion+0x25/0x410 [megaraid_sas]
    [<ffffffffc0061edf>] megasas_init_adapter_fusion+0x21f/0x640 [megaraid_sas]
    [<ffffffffc005df17>] megasas_init_fw+0x357/0xd30 [megaraid_sas]
    [<ffffffffc005ef26>] megasas_probe_one.part.33+0x636/0x1100 [megaraid_sas]
    [<ffffffffc005fa36>] megasas_probe_one+0x46/0xc0 [megaraid_sas]
    [<ffffffff813d2ca5>] local_pci_probe+0x45/0xa0
    [<ffffffff813d4222>] pci_device_probe+0x192/0x1b0
    [<ffffffff814e3658>] driver_probe_device+0x2a8/0x460
    [<ffffffff814e38ed>] __driver_attach+0xdd/0xe0
    [<ffffffff814e124c>] bus_for_each_dev+0x6c/0xc0
    [<ffffffff814e2dde>] driver_attach+0x1e/0x20
    [<ffffffff814e2775>] bus_add_driver+0x45/0x270
    [<ffffffff814e4400>] driver_register+0x60/0xe0
unreferenced object 0xffff880454ce3600 (size 192):
  backtrace:
    [<ffffffff8176166a>] kmemleak_alloc+0x4a/0xa0
    [<ffffffff8121801a>] kmem_cache_alloc_trace+0xca/0x1d0
    [<ffffffffc00605d7>] megasas_alloc_cmdlist_fusion+0x77/0xe0 [megaraid_sas]
(gdb) list *megasas_alloc_cmdlist_fusion+0x77
0xd607 is in megasas_alloc_cmdlist_fusion
                (drivers/scsi/megaraid/megaraid_sas_fusion.c:450).
    [<ffffffffc0060ca5>] megasas_alloc_cmds_fusion+0x25/0x410 [megaraid_sas]
    [<ffffffffc0061edf>] megasas_init_adapter_fusion+0x21f/0x640 [megaraid_sas]
    [<ffffffffc005df17>] megasas_init_fw+0x357/0xd30 [megaraid_sas]
    [<ffffffffc005ef26>] megasas_probe_one.part.33+0x636/0x1100 [megaraid_sas]
    [<ffffffffc005fa36>] megasas_probe_one+0x46/0xc0 [megaraid_sas]
    [<ffffffff813d2ca5>] local_pci_probe+0x45/0xa0
    [<ffffffff813d4222>] pci_device_probe+0x192/0x1b0
    [<ffffffff814e3658>] driver_probe_device+0x2a8/0x460
    [<ffffffff814e38ed>] __driver_attach+0xdd/0xe0
    [<ffffffff814e124c>] bus_for_each_dev+0x6c/0xc0
    [<ffffffff814e2dde>] driver_attach+0x1e/0x20
    [<ffffffff814e2775>] bus_add_driver+0x45/0x270
    [<ffffffff814e4400>] driver_register+0x60/0xe0

Signed-off-by: Shu Wang <shuwang@xxxxxxxxxx>
---
 drivers/scsi/megaraid/megaraid_sas_fusion.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index f990ab4d..9855106 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -425,7 +425,7 @@ static int megasas_create_sg_sense_fusion(struct megasas_instance *instance)
 int
 megasas_alloc_cmdlist_fusion(struct megasas_instance *instance)
 {
-	u32 max_mpt_cmd, i;
+	u32 max_mpt_cmd, i, j;
 	struct fusion_context *fusion;
 
 	fusion = instance->ctrl_context;
@@ -450,11 +450,15 @@ megasas_alloc_cmdlist_fusion(struct megasas_instance *instance)
 		fusion->cmd_list[i] = kzalloc(sizeof(struct megasas_cmd_fusion),
 					      GFP_KERNEL);
 		if (!fusion->cmd_list[i]) {
+			for (j = 0; j < i; j++)
+				kfree(fusion->cmd_list[j]);
+			kfree(fusion->cmd_list);
 			dev_err(&instance->pdev->dev,
 				"Failed from %s %d\n",  __func__, __LINE__);
 			return -ENOMEM;
 		}
 	}
+
 	return 0;
 }
 int
-- 
2.5.0