qla2xxx: Fix crash due to null pointer access

commit fc1ffd6cb38a1c1af625b9833c41928039e733f5 upstream.

During code inspection, while investigating following stack trace
seen on one of the test setup, we found out there was possibility
of memory leak becuase driver was not unwinding the stack properly.

This issue has not been reproduced in a test environment or on a
customer setup.

Here's stack trace that was seen.

[1469877.797315] Call Trace:
[1469877.799940]  [<ffffffffa03ab6e9>] qla2x00_mem_alloc+0xb09/0x10c0 [qla2xxx]
[1469877.806980]  [<ffffffffa03ac50a>] qla2x00_probe_one+0x86a/0x1b50 [qla2xxx]
[1469877.814013]  [<ffffffff813b6d01>] ? __pm_runtime_resume+0x51/0xa0
[1469877.820265]  [<ffffffff8157c1f5>] ? _raw_spin_lock_irqsave+0x25/0x90
[1469877.826776]  [<ffffffff8157cd2d>] ? _raw_spin_unlock_irqrestore+0x6d/0x80
[1469877.833720]  [<ffffffff810741d1>] ? preempt_count_sub+0xb1/0x100
[1469877.839885]  [<ffffffff8157cd0c>] ? _raw_spin_unlock_irqrestore+0x4c/0x80
[1469877.846830]  [<ffffffff81319b9c>] local_pci_probe+0x4c/0xb0
[1469877.852562]  [<ffffffff810741d1>] ? preempt_count_sub+0xb1/0x100
[1469877.858727]  [<ffffffff81319c89>] pci_call_probe+0x89/0xb0

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[ bvanassche: Fixed spelling in patch description ]
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 36d62fd5351103889042e3f13cd045ea785e0f93..ebc939e85b7683cfe7179ce326b831b11fba77ce 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -3384,7 +3384,7 @@ qla2x00_mem_alloc(struct qla_hw_data *ha, uint16_t req_len, uint16_t rsp_len,
                                sizeof(struct ct6_dsd), 0,
                                SLAB_HWCACHE_ALIGN, NULL);
                        if (!ctx_cachep)
-                               goto fail_free_gid_list;
+                               goto fail_free_srb_mempool;
                }
                ha->ctx_mempool = mempool_create_slab_pool(SRB_MIN_REQ,
                        ctx_cachep);
@@ -3537,7 +3537,7 @@ qla2x00_mem_alloc(struct qla_hw_data *ha, uint16_t req_len, uint16_t rsp_len,
        ha->loop_id_map = kzalloc(BITS_TO_LONGS(LOOPID_MAP_SIZE) * sizeof(long),
            GFP_KERNEL);
        if (!ha->loop_id_map)
-               goto fail_async_pd;
+               goto fail_loop_id_map;
        else {
                qla2x00_set_reserved_loop_ids(ha);
                ql_dbg_pci(ql_dbg_init, ha->pdev, 0x0123,
@@ -3546,6 +3546,8 @@ qla2x00_mem_alloc(struct qla_hw_data *ha, uint16_t req_len, uint16_t rsp_len,
 
        return 0;
 
+fail_loop_id_map:
+       dma_pool_free(ha->s_dma_pool, ha->async_pd, ha->async_pd_dma);
 fail_async_pd:
        dma_pool_free(ha->s_dma_pool, ha->ex_init_cb, ha->ex_init_cb_dma);
 fail_ex_init_cb:
@@ -3573,6 +3575,10 @@ fail_free_ms_iocb:
        dma_pool_free(ha->s_dma_pool, ha->ms_iocb, ha->ms_iocb_dma);
        ha->ms_iocb = NULL;
        ha->ms_iocb_dma = 0;
+
+       if (ha->sns_cmd)
+               dma_free_coherent(&ha->pdev->dev, sizeof(struct sns_cmd_pkt),
+                   ha->sns_cmd, ha->sns_cmd_dma);
 fail_dma_pool:
        if (IS_QLA82XX(ha) || ql2xenabledif) {
                dma_pool_destroy(ha->fcp_cmnd_dma_pool);
@@ -3590,10 +3596,12 @@ fail_free_nvram:
        kfree(ha->nvram);
        ha->nvram = NULL;
 fail_free_ctx_mempool:
-       mempool_destroy(ha->ctx_mempool);
+       if (ha->ctx_mempool)
+               mempool_destroy(ha->ctx_mempool);
        ha->ctx_mempool = NULL;
 fail_free_srb_mempool:
-       mempool_destroy(ha->srb_mempool);
+       if (ha->srb_mempool)
+               mempool_destroy(ha->srb_mempool);
        ha->srb_mempool = NULL;
 fail_free_gid_list:
        dma_free_coherent(&ha->pdev->dev, qla2x00_gid_list_size(ha),