[PATCH 09/33] scsi: qla2xxx: Fix FCE trace enable parsing in debugfs

qla2x00_dfs_fce_write() called kstrtoul() with a NULL result pointer,
so a successful parse would dereference NULL and oops. Worse, the int
return value (0 on success, negative errno on failure) was assigned to
the unsigned long enable flag, inverting the intended logic: a valid
number was treated as "disable" while a parse failure enabled FCE.

Parse the value into enable and propagate parse errors to userspace.

Fixes: 841df27d619e ("scsi: qla2xxx: Move FCE Trace buffer allocation to user control")
Cc: [email protected]
Reported-by: Sashiko <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
---
 drivers/scsi/qla2xxx/qla_dfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/qla2xxx/qla_dfs.c b/drivers/scsi/qla2xxx/qla_dfs.c
index 177d47e92e49..5d08bdbcf70a 100644
--- a/drivers/scsi/qla2xxx/qla_dfs.c
+++ b/drivers/scsi/qla2xxx/qla_dfs.c
@@ -510,7 +510,9 @@ qla2x00_dfs_fce_write(struct file *file, const char __user *buffer,
 		return PTR_ERR(buf);
 	}
 
-	enable = kstrtoul(buf, 0, 0);
+	rc = kstrtoul(buf, 0, &enable);
+	if (rc)
+		goto out_free;
 	rc = count;
 
 	mutex_lock(&ha->fce_mutex);
-- 
2.47.3