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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Marcel Holtmann <marcel@holtmann.org>,
	Johan Hedberg <johan.hedberg@gmail.com>
Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org,
	Ran Menscher <ran.menscher@karambasecurity.com>
Subject: [PATCH 2/2] Bluetooth: check the buffer size for some messages before parsing
Date: Thu, 10 Jan 2019 07:29:17 +0100
Message-ID: <20190110062917.GB15047@kroah.com> (raw)
In-Reply-To: <20190110062833.GA15047@kroah.com>

The L2CAP_CONF_EFS and L2CAP_CONF_RFC messages can be sent from
userspace so their structure sizes need to be checked before parsing
them.

Based on a patch from Ran Menscher.

Reported-by: Ran Menscher <ran.menscher@karambasecurity.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/bluetooth/l2cap_core.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 93daf94565cf..55e48e6efc2b 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -3361,7 +3361,8 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data
 			break;
 
 		case L2CAP_CONF_RFC:
-			if (olen == sizeof(rfc))
+			if ((olen == sizeof(rfc)) &&
+			    (endptr - ptr >= L2CAP_CONF_OPT_SIZE + sizeof(rfc)))
 				memcpy(&rfc, (void *) val, olen);
 			break;
 
@@ -3371,7 +3372,8 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data
 			break;
 
 		case L2CAP_CONF_EFS:
-			if (olen == sizeof(efs)) {
+			if ((olen == sizeof(efs)) &&
+			    (endptr - ptr >= L2CAP_CONF_OPT_SIZE + sizeof(efs))) {
 				remote_efs = 1;
 				memcpy(&efs, (void *) val, olen);
 			}
@@ -3576,7 +3578,8 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
 			break;
 
 		case L2CAP_CONF_RFC:
-			if (olen == sizeof(rfc))
+			if ((olen == sizeof(rfc)) &&
+			    (endptr - ptr >= L2CAP_CONF_OPT_SIZE + sizeof(rfc)))
 				memcpy(&rfc, (void *)val, olen);
 
 			if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) &&
@@ -3596,7 +3599,8 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
 			break;
 
 		case L2CAP_CONF_EFS:
-			if (olen == sizeof(efs)) {
+			if ((olen == sizeof(efs)) &&
+			    (endptr - ptr >= L2CAP_CONF_OPT_SIZE + sizeof(efs))) {
 				memcpy(&efs, (void *)val, olen);
 
 				if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
-- 
2.20.1


  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-10  6:28 [PATCH 1/2] Bluetooth: check message types in l2cap_get_conf_opt Greg Kroah-Hartman
2019-01-10  6:29 ` Greg Kroah-Hartman [this message]
2019-01-10  6:30   ` [PATCH 2/2] Bluetooth: check the buffer size for some messages before parsing Greg Kroah-Hartman
2019-01-18  9:37   ` Marcel Holtmann
2019-01-18 10:21     ` Greg Kroah-Hartman
2019-01-18 11:11       ` Marcel Holtmann
2019-01-18 12:44         ` Marcel Holtmann
2019-01-10 21:02 ` [PATCH 1/2] Bluetooth: check message types in l2cap_get_conf_opt Joe Perches
2019-01-11  5:32   ` Greg Kroah-Hartman
2019-01-18  9:35 ` Marcel Holtmann
2019-01-18 10:19   ` Greg Kroah-Hartman
2019-01-18 11:09     ` Marcel Holtmann
2019-01-18 12:08       ` Marcel Holtmann

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