There may be a potential null pointer risk if offset value is
less than 0 when doing memcmp in btmtk_process_coredump().
Check offset is valid before doing memcmp.
Signed-off-by: Chris Lu <chris.lu@xxxxxxxxxxxx>
Co-developed-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
---
v2: fix typo
v3: fix bot checking error
v4: reduce variable 'offset' declaration in v3
---
drivers/bluetooth/btmtk.c | 12 ++++++------
drivers/bluetooth/btmtk.h | 1 +
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
index 786f775196ae..9cc789272ab7 100644
--- a/drivers/bluetooth/btmtk.c
+++ b/drivers/bluetooth/btmtk.c
@@ -395,12 +395,12 @@ int btmtk_process_coredump(struct hci_dev *hdev, struct sk_buff *skb)
/* Mediatek coredump data would be more than MTK_COREDUMP_NUM */
if (data->cd_info.cnt > MTK_COREDUMP_NUM &&
- skb->len > sizeof(MTK_COREDUMP_END) &&
- !memcmp((char *)&skb->data[skb->len - sizeof(MTK_COREDUMP_END)],
- MTK_COREDUMP_END, sizeof(MTK_COREDUMP_END) - 1)) {
- bt_dev_info(hdev, "Mediatek coredump end");
- hci_devcd_complete(hdev);
- }
+ skb->len > MTK_COREDUMP_END_LEN)
+ if (!memcmp((char *)&skb->data[skb->len - MTK_COREDUMP_END_LEN],
+ MTK_COREDUMP_END, MTK_COREDUMP_END_LEN - 1)) {
+ bt_dev_info(hdev, "Mediatek coredump end");
+ hci_devcd_complete(hdev);
+ }
break;
}
diff --git a/drivers/bluetooth/btmtk.h b/drivers/bluetooth/btmtk.h
index 68309dfe076a..56f5502baadf 100644
--- a/drivers/bluetooth/btmtk.h
+++ b/drivers/bluetooth/btmtk.h
@@ -24,6 +24,7 @@
#define MTK_COREDUMP_SIZE (1024 * 1000)
#define MTK_COREDUMP_END "coredump end"
+#define MTK_COREDUMP_END_LEN (sizeof(MTK_COREDUMP_END))
#define MTK_COREDUMP_NUM 255
enum {
--
2.18.0
