From: Ruihan Li lrh2000@pku.edu.cn

commit 000c2fa2c144c499c881a101819cf1936a1f7cf2 upstream.

Previously, channel open messages were always sent to monitors on the first ioctl() call for unbound HCI sockets, even if the command and arguments were completely invalid. This can leave an exploitable hole with the abuse of invalid ioctl calls.

This commit hardens the ioctl processing logic by first checking if the command is valid, and immediately returning with an ENOIOCTLCMD error code if it is not. This ensures that ioctl calls with invalid commands are free of side effects, and increases the difficulty of further exploitation by forcing exploitation to find a way to pass a valid command first.

Signed-off-by: Ruihan Li lrh2000@pku.edu.cn Co-developed-by: Marcel Holtmann marcel@holtmann.org Signed-off-by: Marcel Holtmann marcel@holtmann.org Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Dragos-Marian Panait dragos.panait@windriver.com --- net/bluetooth/hci_sock.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index 837b0767892e..9b1658346396 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -968,6 +968,34 @@ static int hci_sock_ioctl(struct socket *sock, unsigned int cmd,

BT_DBG("cmd %x arg %lx", cmd, arg);

+ /* Make sure the cmd is valid before doing anything */ + switch (cmd) { + case HCIGETDEVLIST: + case HCIGETDEVINFO: + case HCIGETCONNLIST: + case HCIDEVUP: + case HCIDEVDOWN: + case HCIDEVRESET: + case HCIDEVRESTAT: + case HCISETSCAN: + case HCISETAUTH: + case HCISETENCRYPT: + case HCISETPTYPE: + case HCISETLINKPOL: + case HCISETLINKMODE: + case HCISETACLMTU: + case HCISETSCOMTU: + case HCIINQUIRY: + case HCISETRAW: + case HCIGETCONNINFO: + case HCIGETAUTHINFO: + case HCIBLOCKADDR: + case HCIUNBLOCKADDR: + break; + default: + return -ENOIOCTLCMD; + } + lock_sock(sk);

if (hci_pi(sk)->channel != HCI_CHANNEL_RAW) {