shared/gatt-db: Fix munmap_chunk invalid pointer

PTS test GATT/CL/GAD/BV-03-C published a service starting at handle 0xfffd and ending at 0xffff.
This resets the next_handle to 0 in gatt_db_insert_service() instead of setting it to 0x10000. Other services are added later.
This could end-up by a crash in db_hash_update() if not enough space has been allocated for hash.iov and some entries are overwritten.
---
v1 -> v2: Replace next_handle by last_handle
Check empty db using gatt_db_isempty(db) instead of
next_handle == 0
Add robustness unit test to check that gatt_db_get_hash()
doesn't crash

---
 src/shared/gatt-db.c | 18 +++++-----
 unit/test-gatt.c     | 78 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 86 insertions(+), 10 deletions(-)

index 676f963ec..27d588677 100644
@@ -58,7 +58,7 @@ struct gatt_db {
 	struct bt_crypto *crypto;
 	uint8_t hash[16];
 	unsigned int hash_id;
-	uint16_t next_handle;
+	uint16_t last_handle;
 	struct queue *services;
 
 	struct queue *notify_list;

@@ -255,7 +255,7 @@ struct gatt_db *gatt_db_new(void)
 	db->crypto = bt_crypto_new();
 	db->services = queue_new();
 	db->notify_list = queue_new();
-	db->next_handle = 0x0001;
+	db->last_handle = 0x0000;
 
 	return gatt_db_ref(db);
 }

@@ -356,14 +356,14 @@ static bool db_hash_update(void *user_data)
 
 	db->hash_id = 0;
 
-	if (!db->next_handle)
+	if (gatt_db_isempty(db))
 		return false;
 
-	hash.iov = new0(struct iovec, db->next_handle);
+	hash.iov = new0(struct iovec, db->last_handle + 1);
 	hash.i = 0;
 
 	gatt_db_foreach_service(db, NULL, service_gen_hash_m, &hash);
-	bt_crypto_gatt_hash(db->crypto, hash.iov, db->next_handle, db->hash);
+	bt_crypto_gatt_hash(db->crypto, hash.iov, db->last_handle + 1, db->hash);
 
 	for (i = 0; i < hash.i; i++)
 		free(hash.iov[i].iov_base);

@@ -624,7 +624,7 @@ bool gatt_db_clear_range(struct gatt_db *db, uint16_t start_handle,
 
 done:
 	if (gatt_db_isempty(db))
-		db->next_handle = 0;
+		db->last_handle = 0;
 
 	return true;
 }

@@ -700,7 +700,7 @@ struct gatt_db_attribute *gatt_db_insert_service(struct gatt_db *db,
 		return NULL;
 
 	if (!handle)
-		handle = db->next_handle;
+		handle = db->last_handle + 1;
 
 	if (num_handles < 1 || (handle + num_handles - 1) > UINT16_MAX)
 		return NULL;

@@ -747,8 +747,8 @@ struct gatt_db_attribute *gatt_db_insert_service(struct gatt_db *db,
 	service->attributes[0]->handle = handle;
 	service->num_handles = num_handles;
 
-	/* Fast-forward next_handle if the new service was added to the end */
-	db->next_handle = MAX(handle + num_handles, db->next_handle);
+	/* Fast-forward last_handle if the new service was added to the end */
+	db->last_handle = MAX(handle + num_handles - 1, db->last_handle);
 
 	return service->attributes[0];
 

2.34.1

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list. This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=814595

---Test result---

Test Summary:

CheckPatch                    FAIL      0.83 seconds
GitLint                       PASS      0.32 seconds
BuildEll                      PASS      24.16 seconds
BluezMake                     PASS      697.41 seconds
MakeCheck                     PASS      11.58 seconds
MakeDistcheck                 PASS      160.25 seconds
CheckValgrind                 PASS      222.11 seconds
CheckSmatch                   PASS      326.66 seconds
bluezmakeextell               PASS      106.59 seconds
IncrementalBuild              PASS      663.30 seconds
ScanBuild                     PASS      935.33 seconds

Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
[BlueZ,v2] shared/gatt-db: Fix munmap_chunk invalid pointer WARNING:LONG_LINE: line length of 81 exceeds 80 columns #105: FILE: src/shared/gatt-db.c:366:
+ bt_crypto_gatt_hash(db->crypto, hash.iov, db->last_handle + 1, db->hash);

WARNING:LONG_LINE_COMMENT: line length of 89 exceeds 80 columns #218: FILE: unit/test-gatt.c:2413:
+ /* test that gatt_db_get_hash is able to manage unordered db and doesn't crash */

/github/workspace/src/src/13511878.patch total: 0 errors, 2 warnings, 163 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.

/github/workspace/src/src/13511878.patch has style problems, please review.

NOTE: Ignored message types: COMMIT_MESSAGE COMPLEX_MACRO CONST_STRUCT FILE_PATH_CHANGES MISSING_SIGN_OFF PREFER_PACKED SPDX_LICENSE_TAG SPLIT_STRING SSCANF_TO_KSTRTO

NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

---
Regards,
Linux Bluetooth