mirror of
https://github.com/Divested-Mobile/DivestOS-Build.git
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91 lines
2.9 KiB
Diff
91 lines
2.9 KiB
Diff
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From 364a1d99624e8dca6501d98166efbb8061362970 Mon Sep 17 00:00:00 2001
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From: Hui Peng <phui@google.com>
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Date: Tue, 16 May 2023 02:09:38 +0000
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Subject: [PATCH] Fix an integer underflow in build_read_multi_rsp
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When p_buf->len is mtu - 1 and p_cmd->multi_req.variable_len
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evaluates to true, integer underflow is triggered
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in the following line, resulting OOB access.
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```
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len = p_rsp->attr_value.len - (total_len - mtu);
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```
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Bug: 273874525
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Test: manual
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Ignore-AOSP-First: security
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Tag: #security
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(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:85f4d53c7bf90b806639a3a302f0007ffb3b9f23)
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Merged-In: Ia60dd829ff9152c083de1f4c1265bb3ad595dcc4
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Change-Id: Ia60dd829ff9152c083de1f4c1265bb3ad595dcc4
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---
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system/stack/gatt/gatt_sr.cc | 32 +++++++++++++++++---------------
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1 file changed, 17 insertions(+), 15 deletions(-)
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diff --git a/system/stack/gatt/gatt_sr.cc b/system/stack/gatt/gatt_sr.cc
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index f2a3e22414..ce00ef7428 100644
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--- a/system/stack/gatt/gatt_sr.cc
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+++ b/system/stack/gatt/gatt_sr.cc
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@@ -21,6 +21,7 @@
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* this file contains the GATT server functions
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*
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******************************************************************************/
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+#include <algorithm>
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#include <string.h>
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#include "bt_target.h"
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@@ -178,37 +179,38 @@ static void build_read_multi_rsp(tGATT_SR_CMD* p_cmd, uint16_t mtu) {
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}
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if (p_rsp != NULL) {
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- total_len = (p_buf->len + p_rsp->attr_value.len);
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+ total_len = p_buf->len;
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if (p_cmd->multi_req.variable_len) {
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total_len += 2;
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}
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if (total_len > mtu) {
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- /* just send the partial response for the overflow case */
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- len = p_rsp->attr_value.len - (total_len - mtu);
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+ VLOG(1) << "Buffer space not enough for this data item, skipping";
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+ break;
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+ }
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+
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+ len = std::min((size_t) p_rsp->attr_value.len, mtu - total_len);
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+
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+ if (len == 0) {
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+ VLOG(1) << "Buffer space not enough for this data item, skipping";
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+ break;
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+ }
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+
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+ if (len < p_rsp->attr_value.len) {
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is_overflow = true;
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VLOG(1) << StringPrintf(
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"multi read overflow available len=%zu val_len=%d", len,
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p_rsp->attr_value.len);
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- } else {
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- len = p_rsp->attr_value.len;
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}
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if (p_cmd->multi_req.variable_len) {
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- UINT16_TO_STREAM(p, len);
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+ UINT16_TO_STREAM(p, (uint16_t) len);
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p_buf->len += 2;
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}
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if (p_rsp->attr_value.handle == p_cmd->multi_req.handles[ii]) {
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- // check for possible integer overflow
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- if (p_buf->len + len <= UINT16_MAX) {
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- memcpy(p, p_rsp->attr_value.value, len);
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- if (!is_overflow) p += len;
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- p_buf->len += len;
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- } else {
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- p_cmd->status = GATT_NOT_FOUND;
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- break;
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- }
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+ ARRAY_TO_STREAM(p, p_rsp->attr_value.value, (uint16_t) len);
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+ p_buf->len += (uint16_t) len;
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} else {
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p_cmd->status = GATT_NOT_FOUND;
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break;
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