[PATCH] qedi: Fix a possible sleep-in-atomic bug in qedi_process_tmf_resp

From: Jia-Ju Bai
Date: Wed Dec 13 2017 - 04:09:11 EST


The driver may sleep under a spinlock.
The function call path is:
qedi_cpu_offline (acquire the spinlock)
qedi_fp_process_cqes
qedi_mtask_completion
qedi_process_tmf_resp
kzalloc(GFP_KERNEL) --> may sleep

To fix it, GFP_KERNEL is replaced with GFP_ATOMIC.

This bug is found by my static analysis tool(DSAC) and checked by my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/scsi/qedi/qedi_fw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedi/qedi_fw.c b/drivers/scsi/qedi/qedi_fw.c
index bd302d3..20a9259 100644
--- a/drivers/scsi/qedi/qedi_fw.c
+++ b/drivers/scsi/qedi/qedi_fw.c
@@ -198,7 +198,7 @@ static void qedi_process_tmf_resp(struct qedi_ctx *qedi,
cqe_tmp_response = &cqe->cqe_common.iscsi_hdr.tmf_response;

qedi_cmd = task->dd_data;
- qedi_cmd->tmf_resp_buf = kzalloc(sizeof(*resp_hdr_ptr), GFP_KERNEL);
+ qedi_cmd->tmf_resp_buf = kzalloc(sizeof(*resp_hdr_ptr), GFP_ATOMIC);
if (!qedi_cmd->tmf_resp_buf) {
QEDI_ERR(&qedi->dbg_ctx,
"Failed to allocate resp buf, cid=0x%x\n",
--
1.7.9.5