File shared-gatt-server-Fix-heap-overflow-when-appending-.patch of Package bluez.25541
From 591c546c536b42bef696d027f64aa22434f8c3f0 Mon Sep 17 00:00:00 2001
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date: Tue, 8 Jun 2021 16:46:49 -0700
Subject: [PATCH] shared/gatt-server: Fix heap overflow when appending prepare
writes
The code shall check if the prepare writes would append more the
allowed maximum attribute length.
Fixes https://github.com/bluez/bluez/security/advisories/GHSA-479m-xcq5-9g2q
---
src/shared/gatt-server.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
Index: bluez-5.48/src/shared/gatt-server.c
===================================================================
--- bluez-5.48.orig/src/shared/gatt-server.c
+++ bluez-5.48/src/shared/gatt-server.c
@@ -756,6 +756,20 @@ static void write_complete_cb(struct gat
async_write_op_destroy(op);
}
+static uint8_t check_length(uint16_t length, uint16_t offset)
+{
+ if (length > BT_ATT_MAX_VALUE_LEN)
+ return BT_ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LEN;
+
+ if (offset > BT_ATT_MAX_VALUE_LEN)
+ return BT_ATT_ERROR_INVALID_OFFSET;
+
+ if (length + offset > BT_ATT_MAX_VALUE_LEN)
+ return BT_ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LEN;
+
+ return 0;
+}
+
static void write_cb(uint8_t opcode, const void *pdu,
uint16_t length, void *user_data)
{
@@ -782,6 +796,10 @@ static void write_cb(uint8_t opcode, con
(opcode == BT_ATT_OP_WRITE_REQ) ? "Req" : "Cmd",
handle);
+ ecode = check_length(length, 0);
+ if (ecode)
+ goto error;
+
ecode = check_permissions(server, attr, BT_ATT_PERM_WRITE |
BT_ATT_PERM_WRITE_AUTHEN |
BT_ATT_PERM_WRITE_ENCRYPT);
@@ -1210,6 +1228,10 @@ static void prep_write_cb(uint8_t opcode
util_debug(server->debug_callback, server->debug_data,
"Prep Write Req - handle: 0x%04x", handle);
+ ecode = check_length(length, offset);
+ if (ecode)
+ goto error;
+
ecode = check_permissions(server, attr, BT_ATT_PERM_WRITE |
BT_ATT_PERM_WRITE_AUTHEN |
BT_ATT_PERM_WRITE_ENCRYPT);