DivestOS/Patches/LineageOS-17.1/android_system_bt/351445.patch

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Hui Peng <phui@google.com>
Date: Wed, 4 Jan 2023 22:45:13 +0000
Subject: [PATCH] Fix an OOB write in SDP_AddAttribute
When the `attr_pad` becomes full, it is possible
that un index of `-1` is computed write
a zero byte to `p_val`, rusulting OOB write.
```
p_val[SDP_MAX_PAD_LEN - p_rec->free_pad_ptr - 1] = '\0';
```
This is a backport of I937d22a2df26fca1d7f06b10182c4e713ddfed1b
Bug: 261867748
Test: manual
Tag: #security
Ignore-AOSP-First: security
Change-Id: Ibdda754e628cfc9d1706c14db114919a15d8d6b1
(cherry picked from commit cc527a97f78a2999a0156a579e488afe9e3675b2)
Merged-In: Ibdda754e628cfc9d1706c14db114919a15d8d6b1
---
stack/sdp/sdp_db.cc | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/stack/sdp/sdp_db.cc b/stack/sdp/sdp_db.cc
index ea5b84d23..4130ae71a 100644
--- a/stack/sdp/sdp_db.cc
+++ b/stack/sdp/sdp_db.cc
@@ -362,6 +362,11 @@ bool SDP_AddAttribute(uint32_t handle, uint16_t attr_id, uint8_t attr_type,
uint16_t xx, yy, zz;
tSDP_RECORD* p_rec = &sdp_cb.server_db.record[0];
+ if (p_val == nullptr) {
+ SDP_TRACE_WARNING("Trying to add attribute with p_val == nullptr, skipped");
+ return (false);
+ }
+
if (sdp_cb.trace_level >= BT_TRACE_LEVEL_DEBUG) {
if ((attr_type == UINT_DESC_TYPE) ||
(attr_type == TWO_COMP_INT_DESC_TYPE) ||
@@ -398,6 +403,13 @@ bool SDP_AddAttribute(uint32_t handle, uint16_t attr_id, uint8_t attr_type,
if (p_rec->record_handle == handle) {
tSDP_ATTRIBUTE* p_attr = &p_rec->attribute[0];
+ // error out early, no need to look up
+ if (p_rec->free_pad_ptr >= SDP_MAX_PAD_LEN) {
+ SDP_TRACE_ERROR("the free pad for SDP record with handle %d is "
+ "full, skip adding the attribute", handle);
+ return (false);
+ }
+
/* Found the record. Now, see if the attribute already exists */
for (xx = 0; xx < p_rec->num_attributes; xx++, p_attr++) {
/* The attribute exists. replace it */
@@ -437,15 +449,13 @@ bool SDP_AddAttribute(uint32_t handle, uint16_t attr_id, uint8_t attr_type,
attr_len = 0;
}
- if ((attr_len > 0) && (p_val != 0)) {
+ if (attr_len > 0) {
p_attr->len = attr_len;
memcpy(&p_rec->attr_pad[p_rec->free_pad_ptr], p_val, (size_t)attr_len);
p_attr->value_ptr = &p_rec->attr_pad[p_rec->free_pad_ptr];
p_rec->free_pad_ptr += attr_len;
- } else if ((attr_len == 0 &&
- p_attr->len !=
- 0) || /* if truncate to 0 length, simply don't add */
- p_val == 0) {
+ } else if (attr_len == 0 && p_attr->len != 0) {
+ /* if truncate to 0 length, simply don't add */
SDP_TRACE_ERROR(
"SDP_AddAttribute fail, length exceed maximum: ID %d: attr_len:%d ",
attr_id, attr_len);