From: Pan Bian <bianpan2016@xxxxxxx> [ Upstream commit 99a8efbb6e30b72ac98cecf81103f847abffb1e5 ] The variable nfcid_skb is not changed in the callee nfc_hci_get_param() if error occurs. Consequently, the freed variable nfcid_skb will be freed again, resulting in a double free bug. Set nfcid_skb to NULL after releasing it to fix the bug. Signed-off-by: Pan Bian <bianpan2016@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/nfc/st21nfca/core.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/nfc/st21nfca/core.c +++ b/drivers/nfc/st21nfca/core.c @@ -726,6 +726,7 @@ static int st21nfca_hci_complete_target_ NFC_PROTO_FELICA_MASK; } else { kfree_skb(nfcid_skb); + nfcid_skb = NULL; /* P2P in type A */ r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_F_GATE, ST21NFCA_RF_READER_F_NFCID1,