From 79d404a2aa86efe4f1ade51e054318bd811cce71 Mon Sep 17 00:00:00 2001 From: Tomas Bortoli Date: Fri, 1 Nov 2019 21:42:44 +0100 Subject: [PATCH] Bluetooth: Fix invalid-free in bcsp_close() 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 Reported-by: syzbot+a0d209a4676664613e76@syzkaller.appspotmail.com Signed-off-by: Marcel Holtmann Cc: Alexander Potapenko Signed-off-by: Greg Kroah-Hartman --- drivers/bluetooth/hci_bcsp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/bluetooth/hci_bcsp.c b/drivers/bluetooth/hci_bcsp.c index 57a7f4255ac0..ee6c403de6af 100644 --- a/drivers/bluetooth/hci_bcsp.c +++ b/drivers/bluetooth/hci_bcsp.c @@ -605,6 +605,7 @@ static int bcsp_recv(struct hci_uart *hu, const void *data, int count) 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, const void *data, int count) 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, const void *data, int count) 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; -- 2.20.1