From: Tomas Bortoli tomasbortoli@gmail.com
commit cf94da6f502d8caecabd56b194541c873c8a7a3c upstream.
Syzbot reported an invalid-free that I introduced fixing a memleak.
bcsp_recv() also frees bcsp->rx_skb but never nullifies its value. Nullify bcsp->rx_skb every time it is freed.
Signed-off-by: Tomas Bortoli tomasbortoli@gmail.com Reported-by: syzbot+a0d209a4676664613e76@syzkaller.appspotmail.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Cc: Alexander Potapenko glider@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/bluetooth/hci_bcsp.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/bluetooth/hci_bcsp.c +++ b/drivers/bluetooth/hci_bcsp.c @@ -605,6 +605,7 @@ static int bcsp_recv(struct hci_uart *hu if (*ptr == 0xc0) { BT_ERR("Short BCSP packet"); kfree_skb(bcsp->rx_skb); + bcsp->rx_skb = NULL; bcsp->rx_state = BCSP_W4_PKT_START; bcsp->rx_count = 0; } else @@ -620,6 +621,7 @@ static int bcsp_recv(struct hci_uart *hu bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) { BT_ERR("Error in BCSP hdr checksum"); kfree_skb(bcsp->rx_skb); + bcsp->rx_skb = NULL; bcsp->rx_state = BCSP_W4_PKT_DELIMITER; bcsp->rx_count = 0; continue; @@ -644,6 +646,7 @@ static int bcsp_recv(struct hci_uart *hu bscp_get_crc(bcsp));
kfree_skb(bcsp->rx_skb); + bcsp->rx_skb = NULL; bcsp->rx_state = BCSP_W4_PKT_DELIMITER; bcsp->rx_count = 0; continue;