From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: [PATCH 1/2] Bluetooth: check message types in l2cap_get_conf_opt Date: Thu, 10 Jan 2019 07:28:33 +0100 Message-ID: <20190110062833.GA15047@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org To: Marcel Holtmann , Johan Hedberg Return-path: Received: from mail.kernel.org ([198.145.29.99]:37640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726338AbfAJG2h (ORCPT ); Thu, 10 Jan 2019 01:28:37 -0500 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: l2cap_get_conf_opt can handle a "default" message type, but it needs to be verified that it really is the correct type (CONF_EFS or CONF_RFC) before passing it back to the caller. To do this we need to check the return value of this call now and handle the error correctly up the stack. Based on a patch from Ran Menscher. Reported-by: Ran Menscher Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/l2cap_core.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 2a7fb517d460..93daf94565cf 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -2980,6 +2980,10 @@ static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen, break; default: + /* Only CONF_EFS and CONF_RFC are allowed here */ + if ((opt->type != L2CAP_CONF_EFS) && + (opt->type != L2CAP_CONF_RFC)) + return -EPROTO; *val = (unsigned long) opt->val; break; } @@ -3324,7 +3328,7 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data void *endptr = data + data_size; void *req = chan->conf_req; int len = chan->conf_len; - int type, hint, olen; + int type, hint, olen, err; unsigned long val; struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; struct l2cap_conf_efs efs; @@ -3336,7 +3340,10 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data BT_DBG("chan %p", chan); while (len >= L2CAP_CONF_OPT_SIZE) { - len -= l2cap_get_conf_opt(&req, &type, &olen, &val); + err = l2cap_get_conf_opt(&req, &type, &olen, &val); + if (err < 0) + return err; + len -= err; hint = type & L2CAP_CONF_HINT; type &= L2CAP_CONF_MASK; @@ -3539,7 +3546,7 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, struct l2cap_conf_req *req = data; void *ptr = req->data; void *endptr = data + size; - int type, olen; + int type, olen, err; unsigned long val; struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; struct l2cap_conf_efs efs; @@ -3547,7 +3554,10 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data); while (len >= L2CAP_CONF_OPT_SIZE) { - len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); + err = l2cap_get_conf_opt(&rsp, &type, &olen, &val); + if (err < 0) + return err; + len -= err; switch (type) { case L2CAP_CONF_MTU: @@ -3707,7 +3717,7 @@ void __l2cap_connect_rsp_defer(struct l2cap_chan *chan) static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) { - int type, olen; + int type, olen, err; unsigned long val; /* Use sane default values in case a misbehaving remote device * did not send an RFC or extended window size option. @@ -3727,7 +3737,10 @@ static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) return; while (len >= L2CAP_CONF_OPT_SIZE) { - len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); + err = l2cap_get_conf_opt(&rsp, &type, &olen, &val); + if (err < 0) + return; + len -= err; switch (type) { case L2CAP_CONF_RFC: -- 2.20.1