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authorBill Kuzeja <William.Kuzeja@stratus.com>2018-03-23 10:37:25 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-19 08:55:11 +0200
commitb8877993138894eb7e0e71f70cdba6f9c3a56628 (patch)
treeb39da2dac65a3b27e5d4fc0f67962158b4c6f42e
parente4e64ce3fbc470a5b33a79f1a795e4746a7b50bb (diff)
scsi: qla2xxx: Fix small memory leak in qla2x00_probe_one on probe failure
commit 6d6340672ba3a99c4cf7af79c2edf7aa25595c84 upstream. The code that fixes the crashes in the following commit introduced a small memory leak: commit 6a2cf8d3663e ("scsi: qla2xxx: Fix crashes in qla2x00_probe_one on probe failure") Fixing this requires a bit of reworking, which I've explained. Also provide some code cleanup. There is a small window in qla2x00_probe_one where if qla2x00_alloc_queues fails, we end up never freeing req and rsp and leak 0xc0 and 0xc8 bytes respectively (the sizes of req and rsp). I originally put in checks to test for this condition which were based on the incorrect assumption that if ha->rsp_q_map and ha->req_q_map were allocated, then rsp and req were allocated as well. This is incorrect. There is a window between these allocations: ret = qla2x00_mem_alloc(ha, req_length, rsp_length, &req, &rsp); goto probe_hw_failed; [if successful, both rsp and req allocated] base_vha = qla2x00_create_host(sht, ha); goto probe_hw_failed; ret = qla2x00_request_irqs(ha, rsp); goto probe_failed; if (qla2x00_alloc_queues(ha, req, rsp)) { goto probe_failed; [if successful, now ha->rsp_q_map and ha->req_q_map allocated] To simplify this, we should just set req and rsp to NULL after we free them. Sounds simple enough? The problem is that req and rsp are pointers defined in the qla2x00_probe_one and they are not always passed by reference to the routines that free them. Here are paths which can free req and rsp: PATH 1: qla2x00_probe_one ret = qla2x00_mem_alloc(ha, req_length, rsp_length, &req, &rsp); [req and rsp are passed by reference, but if this fails, we currently do not NULL out req and rsp. Easily fixed] PATH 2: qla2x00_probe_one failing in qla2x00_request_irqs or qla2x00_alloc_queues probe_failed: qla2x00_free_device(base_vha); qla2x00_free_req_que(ha, req) qla2x00_free_rsp_que(ha, rsp) PATH 3: qla2x00_probe_one: failing in qla2x00_mem_alloc or qla2x00_create_host probe_hw_failed: qla2x00_free_req_que(ha, req) qla2x00_free_rsp_que(ha, rsp) PATH 1: This should currently work, but it doesn't because rsp and rsp are not set to NULL in qla2x00_mem_alloc. Easily remedied. PATH 2: req and rsp aren't passed in at all to qla2x00_free_device but are derived from ha->req_q_map[0] and ha->rsp_q_map[0]. These are only set up if qla2x00_alloc_queues succeeds. In qla2x00_free_queues, we are protected from crashing if these don't exist because req_qid_map and rsp_qid_map are only set on their allocation. We are guarded in this way: for (cnt = 0; cnt < ha->max_req_queues; cnt++) { if (!test_bit(cnt, ha->req_qid_map)) continue; PATH 3: This works. We haven't freed req or rsp yet (or they were never allocated if qla2x00_mem_alloc failed), so we'll attempt to free them here. To summarize, there are a few small changes to make this work correctly and (and for some cleanup): 1) (For PATH 1) Set *rsp and *req to NULL in case of failure in qla2x00_mem_alloc so these are correctly set to NULL back in qla2x00_probe_one 2) After jumping to probe_failed: and calling qla2x00_free_device, explicitly set rsp and req to NULL so further calls with these pointers do not crash, i.e. the free queue calls in the probe_hw_failed section we fall through to. 3) Fix return code check in the call to qla2x00_alloc_queues. We currently drop the return code on the floor. The probe fails but the caller of the probe doesn't have an error code, so it attaches to pci. This can result in a crash on module shutdown. 4) Remove unnecessary NULL checks in qla2x00_free_req_que, qla2x00_free_rsp_que, and the egregious NULL checks before kfrees and vfrees in qla2x00_mem_free. I tested this out running a scenario where the card breaks at various times during initialization. I made sure I forced every error exit path in qla2x00_probe_one. Cc: <stable@vger.kernel.org> # v4.16 Fixes: 6a2cf8d3663e ("scsi: qla2xxx: Fix crashes in qla2x00_probe_one on probe failure") Signed-off-by: Bill Kuzeja <william.kuzeja@stratus.com> Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/scsi/qla2xxx/qla_os.c44
1 files changed, 21 insertions, 23 deletions
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 1204c1d59bc4..a879c3f4e20c 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -466,9 +466,6 @@ fail_req_map:
static void qla2x00_free_req_que(struct qla_hw_data *ha, struct req_que *req)
{
- if (!ha->req_q_map)
- return;
-
if (IS_QLAFX00(ha)) {
if (req && req->ring_fx00)
dma_free_coherent(&ha->pdev->dev,
@@ -479,17 +476,14 @@ static void qla2x00_free_req_que(struct qla_hw_data *ha, struct req_que *req)
(req->length + 1) * sizeof(request_t),
req->ring, req->dma);
- if (req) {
+ if (req)
kfree(req->outstanding_cmds);
- kfree(req);
- }
+
+ kfree(req);
}
static void qla2x00_free_rsp_que(struct qla_hw_data *ha, struct rsp_que *rsp)
{
- if (!ha->rsp_q_map)
- return;
-
if (IS_QLAFX00(ha)) {
if (rsp && rsp->ring)
dma_free_coherent(&ha->pdev->dev,
@@ -500,8 +494,7 @@ static void qla2x00_free_rsp_que(struct qla_hw_data *ha, struct rsp_que *rsp)
(rsp->length + 1) * sizeof(response_t),
rsp->ring, rsp->dma);
}
- if (rsp)
- kfree(rsp);
+ kfree(rsp);
}
static void qla2x00_free_queues(struct qla_hw_data *ha)
@@ -3083,7 +3076,8 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
goto probe_failed;
/* Alloc arrays of request and response ring ptrs */
- if (qla2x00_alloc_queues(ha, req, rsp)) {
+ ret = qla2x00_alloc_queues(ha, req, rsp);
+ if (ret) {
ql_log(ql_log_fatal, base_vha, 0x003d,
"Failed to allocate memory for queue pointers..."
"aborting.\n");
@@ -3384,8 +3378,15 @@ probe_failed:
}
qla2x00_free_device(base_vha);
-
scsi_host_put(base_vha->host);
+ /*
+ * Need to NULL out local req/rsp after
+ * qla2x00_free_device => qla2x00_free_queues frees
+ * what these are pointing to. Or else we'll
+ * fall over below in qla2x00_free_req/rsp_que.
+ */
+ req = NULL;
+ rsp = NULL;
probe_hw_failed:
qla2x00_mem_free(ha);
@@ -4078,6 +4079,7 @@ fail_npiv_info:
(*rsp)->dma = 0;
fail_rsp_ring:
kfree(*rsp);
+ *rsp = NULL;
fail_rsp:
dma_free_coherent(&ha->pdev->dev, ((*req)->length + 1) *
sizeof(request_t), (*req)->ring, (*req)->dma);
@@ -4085,6 +4087,7 @@ fail_rsp:
(*req)->dma = 0;
fail_req_ring:
kfree(*req);
+ *req = NULL;
fail_req:
dma_free_coherent(&ha->pdev->dev, sizeof(struct ct_sns_pkt),
ha->ct_sns, ha->ct_sns_dma);
@@ -4452,16 +4455,11 @@ qla2x00_mem_free(struct qla_hw_data *ha)
dma_free_coherent(&ha->pdev->dev, ha->init_cb_size,
ha->init_cb, ha->init_cb_dma);
- if (ha->optrom_buffer)
- vfree(ha->optrom_buffer);
- if (ha->nvram)
- kfree(ha->nvram);
- if (ha->npiv_info)
- kfree(ha->npiv_info);
- if (ha->swl)
- kfree(ha->swl);
- if (ha->loop_id_map)
- kfree(ha->loop_id_map);
+ vfree(ha->optrom_buffer);
+ kfree(ha->nvram);
+ kfree(ha->npiv_info);
+ kfree(ha->swl);
+ kfree(ha->loop_id_map);
ha->srb_mempool = NULL;
ha->ctx_mempool = NULL;