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From: Huai-Yuan Liu <qq810974084@gmail.com>
To: james.smart@broadcom.com,
	dick.kennedy@broadcom.com,
	jejb@linux.ibm.com,
	martin.petersen@oracle.com
Cc: linux-scsi@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	baijiaju1990@outlook.com,
	Huai-Yuan Liu <qq810974084@gmail.com>
Subject: 
Date: Wed,  3 Apr 2024 09:27:15 +0800
Message-Id: <20240403012715.3058-1-qq810974084@gmail.com>
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Subject: [PATCH] scsi: lpfc: Fix a possible null pointer dereference

In function lpfc_xcvr_data_show, the memory allocation with kmalloc might
fail, thereby making rdp_context a null pointer. In the following context 
and functions that use this pointer, there are dereferencing operations,
leading to null pointer dereference.

To fix this issue, a null pointer check should be added. If it is null, 
write error message and jump to 'out_free_rdp'.

Fixes: 479b0917e447 ("scsi: lpfc: Create a sysfs entry called lpfc_xcvr_data for transceiver info")
Signed-off-by: Huai-Yuan Liu <qq810974084@gmail.com>
---
 drivers/scsi/lpfc/lpfc_attr.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index b1c9107d3408..b11e5114b7f2 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -1904,6 +1904,11 @@ lpfc_xcvr_data_show(struct device *dev, struct device_attribute *attr,
 
 	/* Get transceiver information */
 	rdp_context = kmalloc(sizeof(*rdp_context), GFP_KERNEL);
+	if (!rdp_context) {
+		len = scnprintf(buf, PAGE_SIZE - len,
+				"ERROR: Not enough memory\n");
+		goto out_free_rdp;
+	}
 
 	rc = lpfc_get_sfp_info_wait(phba, rdp_context);
 	if (rc) {
-- 
2.34.1