diff mbox series

[BlueZ] gatt-server: Flush notify multiple buffer when full and fix overflow

Message ID 20210612093236.5293-1-surban@surban.net (mailing list archive)
State Superseded
Headers show
Series [BlueZ] gatt-server: Flush notify multiple buffer when full and fix overflow | expand

Commit Message

Sebastian Urban June 12, 2021, 9:32 a.m. UTC 
This fixes the calculation of available buffer space in
bt_gatt_server_send_notification and sends pending notifications
immediately when there is no more room to add a notification.

Previously there was a buffer overflow caused by incorrect calculation
of available buffer space: data->offset can equal data->len
from a previous call to this function, leading
(data->len - data->offset) to underflow after data->offset += 2.
---
 src/shared/gatt-server.c | 43 +++++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 7 deletions(-)

Comments

bluez.test.bot@gmail.com June 12, 2021, 9:56 a.m. UTC | #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=499291

---Test result---

Test Summary:
CheckPatch                    PASS      0.52 seconds
GitLint                       PASS      0.12 seconds
Prep - Setup ELL              PASS      47.89 seconds
Build - Prep                  PASS      0.15 seconds
Build - Configure             PASS      8.11 seconds
Build - Make                  FAIL      10.16 seconds
Make Check                    FAIL      0.57 seconds
Make Distcheck                PASS      243.02 seconds
Build w/ext ELL - Configure   PASS      8.14 seconds
Build w/ext ELL - Make        FAIL      9.66 seconds

Details
##############################
Test: CheckPatch - PASS
Desc: Run checkpatch.pl script with rule in .checkpatch.conf

##############################
Test: GitLint - PASS
Desc: Run gitlint with rule in .gitlint

##############################
Test: Prep - Setup ELL - PASS
Desc: Clone, build, and install ELL

##############################
Test: Build - Prep - PASS
Desc: Prepare environment for build

##############################
Test: Build - Configure - PASS
Desc: Configure the BlueZ source tree

##############################
Test: Build - Make - FAIL
Desc: Build the BlueZ source tree
Output:
src/shared/gatt-server.c:1693:6: error: no previous declaration for ‘notify_append_le16’ [-Werror=missing-declarations]
 1693 | bool notify_append_le16(struct nfy_mult_data *data, uint16_t value)
      |      ^~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[1]: *** [Makefile:6955: src/shared/gatt-server.lo] Error 1
make: *** [Makefile:4134: all] Error 2


##############################
Test: Make Check - FAIL
Desc: Run 'make check'
Output:
src/shared/gatt-server.c:1693:6: error: no previous declaration for ‘notify_append_le16’ [-Werror=missing-declarations]
 1693 | bool notify_append_le16(struct nfy_mult_data *data, uint16_t value)
      |      ^~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[1]: *** [Makefile:6955: src/shared/gatt-server.lo] Error 1
make: *** [Makefile:10406: check] Error 2


##############################
Test: Make Distcheck - PASS
Desc: Run distcheck to check the distribution

##############################
Test: Build w/ext ELL - Configure - PASS
Desc: Configure BlueZ source with '--enable-external-ell' configuration

##############################
Test: Build w/ext ELL - Make - FAIL
Desc: Build BlueZ source with '--enable-external-ell' configuration
Output:
src/shared/gatt-server.c:1693:6: error: no previous declaration for ‘notify_append_le16’ [-Werror=missing-declarations]
 1693 | bool notify_append_le16(struct nfy_mult_data *data, uint16_t value)
      |      ^~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[1]: *** [Makefile:6955: src/shared/gatt-server.lo] Error 1
make: *** [Makefile:4134: all] Error 2




---
Regards,
Linux Bluetooth
diff mbox series

Patch

diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
index 970c35f94..5dbe9d66c 100644
--- a/src/shared/gatt-server.c
+++ b/src/shared/gatt-server.c
@@ -1690,6 +1690,17 @@  static bool notify_multiple(void *user_data)
 	return false;
 }
 
+bool notify_append_le16(struct nfy_mult_data *data, uint16_t value)
+{
+	if (data->offset + sizeof(value) > data->len)
+		return false;
+
+	put_le16(value, data->pdu + data->offset);
+	data->offset += sizeof(value);
+
+	return true;
+}
+
 bool bt_gatt_server_send_notification(struct bt_gatt_server *server,
 					uint16_t handle, const uint8_t *value,
 					uint16_t length, bool multiple)
@@ -1700,23 +1711,35 @@  bool bt_gatt_server_send_notification(struct bt_gatt_server *server,
 	if (!server || (length && !value))
 		return false;
 
-	if (multiple)
+	if (multiple) {
 		data = server->nfy_mult;
 
+		/* flush buffered data if this request hits buffer size limit */
+		if (data && data->offset > 0 &&
+				data->len - data->offset < 4 + length) {
+			if (server->nfy_mult->id)
+				timeout_remove(server->nfy_mult->id);
+			notify_multiple(server);
+			/* data has been freed by notify_multiple */
+			data = NULL;
+		}
+	}
+
 	if (!data) {
 		data = new0(struct nfy_mult_data, 1);
 		data->len = bt_att_get_mtu(server->att) - 1;
 		data->pdu = malloc(data->len);
 	}
 
-	put_le16(handle, data->pdu + data->offset);
-	data->offset += 2;
-
-	length = MIN(data->len - data->offset, length);
+	if (!notify_append_le16(data, handle))
+		goto error;
 
 	if (multiple) {
-		put_le16(length, data->pdu + data->offset);
-		data->offset += 2;
+		length = MIN(data->len - data->offset - 2, length);
+		if (!notify_append_le16(data, length))
+			goto error;
+	} else {
+		length = MIN(data->len - data->offset, length);
 	}
 
 	memcpy(data->pdu + data->offset, value, length);
@@ -1740,6 +1763,12 @@  bool bt_gatt_server_send_notification(struct bt_gatt_server *server,
 	free(data);
 
 	return result;
+
+error:
+	if (data)
+		free(data);
+
+	return false;
 }
 
 struct ind_data {