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[BlueZ,09/12] gatt-server: Fix integer overflow due to cast operation

Message ID 20240704102617.1132337-10-hadess@hadess.net
State New
Headers show
Series Fix a number of static analysis issues #5 | expand

Commit Message

Bastien Nocera July 4, 2024, 10:24 a.m. UTC 
Error: INTEGER_OVERFLOW (CWE-190): [#def25] [important]
bluez-5.76/src/shared/gatt-server.c:927:2: cast_overflow: Truncation due to cast operation on "((unsigned int)mtu - 1U < len) ? (unsigned int)mtu - 1U : len" from 32 to 16 bits.
bluez-5.76/src/shared/gatt-server.c:927:2: overflow_sink: "((unsigned int)mtu - 1U < len) ? (unsigned int)mtu - 1U : len", which might have overflowed, is passed to "bt_att_chan_send(op->chan, rsp_opcode, (len ? value : NULL), (((unsigned int)mtu - 1U < len) ? (unsigned int)mtu - 1U : len), NULL, NULL, NULL)".
925|	rsp_opcode = get_read_rsp_opcode(op->opcode);
926|
927|->	bt_att_chan_send_rsp(op->chan, rsp_opcode, len ? value : NULL,
928|					MIN((unsigned int) mtu - 1, len));
929|	async_read_op_destroy(op);
---
 src/shared/gatt-server.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
index c587553d655d..6ced21248b75 100644
--- a/src/shared/gatt-server.c
+++ b/src/shared/gatt-server.c
@@ -908,7 +908,7 @@  static void read_complete_cb(struct gatt_db_attribute *attr, int err,
 	struct async_read_op *op = user_data;
 	struct bt_gatt_server *server = op->server;
 	uint8_t rsp_opcode;
-	uint16_t mtu;
+	size_t mtu;
 	uint16_t handle;
 
 	DBG(server, "Read Complete: err %d", err);
@@ -916,7 +916,7 @@  static void read_complete_cb(struct gatt_db_attribute *attr, int err,
 	mtu = bt_att_get_mtu(server->att);
 	handle = gatt_db_attribute_get_handle(attr);
 
-	if (err) {
+	if (err || mtu <= 1) {
 		bt_att_chan_send_error_rsp(op->chan, op->opcode, handle, err);
 		async_read_op_destroy(op);
 		return;
@@ -925,7 +925,7 @@  static void read_complete_cb(struct gatt_db_attribute *attr, int err,
 	rsp_opcode = get_read_rsp_opcode(op->opcode);
 
 	bt_att_chan_send_rsp(op->chan, rsp_opcode, len ? value : NULL,
-					MIN((unsigned int) mtu - 1, len));
+					MIN(mtu - 1, len));
 	async_read_op_destroy(op);
 }