4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Myungho Jung <mhjungk@xxxxxxxxx>
commit 1dc2d785156cbdc80806c32e8d2c7c735d0b4721 upstream.
h4_recv_buf() callers store the return value to socket buffer and
recursively pass the buffer to h4_recv_buf() without protection. So,
ERR_PTR returned from h4_recv_buf() can be dereferenced, if called again
before setting the socket buffer to NULL from previous error. Check if
skb is ERR_PTR in h4_recv_buf().
Reported-by: syzbot+017a32f149406df32703@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Myungho Jung <mhjungk@xxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/bluetooth/hci_h4.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/bluetooth/hci_h4.c
+++ b/drivers/bluetooth/hci_h4.c
@@ -174,6 +174,10 @@ struct sk_buff *h4_recv_buf(struct hci_d
struct hci_uart *hu = hci_get_drvdata(hdev);
u8 alignment = hu->alignment ? hu->alignment : 1;
+ /* Check for error from previous call */
+ if (IS_ERR(skb))
+ skb = NULL;
+
while (count) {
int i, len;
