4.19-stable review patch. If anyone has any objections, please let me know.
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From: Myungho Jung mhjungk@gmail.com
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@syzkaller.appspotmail.com Signed-off-by: Myungho Jung mhjungk@gmail.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/bluetooth/h4_recv.h | 4 ++++ drivers/bluetooth/hci_h4.c | 4 ++++ 2 files changed, 8 insertions(+)
--- a/drivers/bluetooth/h4_recv.h +++ b/drivers/bluetooth/h4_recv.h @@ -60,6 +60,10 @@ static inline struct sk_buff *h4_recv_bu const struct h4_recv_pkt *pkts, int pkts_count) { + /* Check for error from previous call */ + if (IS_ERR(skb)) + skb = NULL; + while (count) { int i, len;
--- 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;