Dear Chris,
Am 12.07.23 um 07:18 schrieb Chris Lu:
There may be a potential null pointer risk if offset value is
less than 0 when doing memcmp in btmtk_process_coredump().
Checking offset is valid before doing memcmp.
Use imperative mood: Check offset …
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
---
drivers/bluetooth/btmtk.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
index 786f775196ae..0f290430ae0e 100644
--- a/drivers/bluetooth/btmtk.c
+++ b/drivers/bluetooth/btmtk.c
@@ -370,7 +370,7 @@ EXPORT_SYMBOL_GPL(btmtk_register_coredump);
int btmtk_process_coredump(struct hci_dev *hdev, struct sk_buff *skb)
{
struct btmediatek_data *data = hci_get_priv(hdev);
- int err;
+ int err, offset;
if (!IS_ENABLED(CONFIG_DEV_COREDUMP))
return 0;
@@ -392,15 +392,15 @@ int btmtk_process_coredump(struct hci_dev *hdev, struct sk_buff *skb)
if (err < 0)
break;
data->cd_info.cnt++;
+ offset = skb->len - sizeof(MTK_COREDUMP_END);
For `sizeof()` shouldn’t you use `size_t`? But that is unsigned of
course. Maybe ssize_t then?
/* 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);
- }
+ if (data->cd_info.cnt > MTK_COREDUMP_NUM && offset > 0)
Why not keep it like before, and just add the condition `skb->len <
sizeof(MTK_COREDUMP_END)`? The compiler is probably going to optimize so
the value is not calculated twice.
Kind regards,
Paul
+ if (!memcmp((char *)&skb->data[offset], MTK_COREDUMP_END,
+ sizeof(MTK_COREDUMP_END) - 1)) {
+ bt_dev_info(hdev, "Mediatek coredump end");
+ hci_devcd_complete(hdev);
+ }
break;
}
