diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 036d887dec34..a1d249f42be7 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -3045,13 +3045,24 @@ static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
 	return NULL;
 }
 
-static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
-				     unsigned long *val)
+static inline int l2cap_get_conf_opt(void **ptr, void *end, int *type,
+				     int *olen, unsigned long *val)
 {
 	struct l2cap_conf_opt *opt = *ptr;
 	int len;
 
+	/* opt->len is attacker-controlled. Validate that the full option
+	 * (header + value) actually fits in the buffer before touching
+	 * opt->val, otherwise the switch below reads past the end of the
+	 * caller's buffer.
+	 */
+	if (end - *ptr < L2CAP_CONF_OPT_SIZE)
+		return -EINVAL;
+
 	len = L2CAP_CONF_OPT_SIZE + opt->len;
+	if (end - *ptr < len)
+		return -EINVAL;
+
 	*ptr += len;
 
 	*type = opt->type;
@@ -3423,6 +3434,7 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data
 	void *ptr = rsp->data;
 	void *endptr = data + data_size;
 	void *req = chan->conf_req;
+	void *req_end = req + chan->conf_len;
 	int len = chan->conf_len;
 	int type, hint, olen;
 	unsigned long val;
@@ -3436,9 +3448,11 @@ 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);
-		if (len < 0)
+		int ret = l2cap_get_conf_opt(&req, req_end, &type, &olen, &val);
+
+		if (ret < 0)
 			break;
+		len -= ret;
 
 		hint  = type & L2CAP_CONF_HINT;
 		type &= L2CAP_CONF_MASK;
@@ -3666,6 +3680,7 @@ 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;
+	void *rsp_end = rsp + len;
 	int type, olen;
 	unsigned long val;
 	struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
@@ -3674,9 +3689,11 @@ 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);
-		if (len < 0)
+		int ret = l2cap_get_conf_opt(&rsp, rsp_end, &type, &olen, &val);
+
+		if (ret < 0)
 			break;
+		len -= ret;
 
 		switch (type) {
 		case L2CAP_CONF_MTU:
@@ -3927,6 +3944,7 @@ static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
 {
 	int type, olen;
 	unsigned long val;
+	void *rsp_end = rsp + len;
 	/* Use sane default values in case a misbehaving remote device
 	 * did not send an RFC or extended window size option.
 	 */
@@ -3945,9 +3963,11 @@ 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);
-		if (len < 0)
+		int ret = l2cap_get_conf_opt(&rsp, rsp_end, &type, &olen, &val);
+
+		if (ret < 0)
 			break;
+		len -= ret;
 
 		switch (type) {
 		case L2CAP_CONF_RFC: