linux-bluetooth.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt
@ 2021-07-28  7:51 Desmond Cheong Zhi Xi
  2021-07-28  9:07 ` [v2] " bluez.test.bot
  2021-07-29 11:38 ` [PATCH v2] " Marcel Holtmann
  0 siblings, 2 replies; 3+ messages in thread
From: Desmond Cheong Zhi Xi @ 2021-07-28  7:51 UTC (permalink / raw)
  To: marcel, johan.hedberg, luiz.dentz, davem, kuba
  Cc: Desmond Cheong Zhi Xi, linux-bluetooth, netdev, linux-kernel,
	skhan, gregkh, linux-kernel-mentees, syzbot+66264bf2fd0476be7e6c

Syzbot reported a corrupted list in kobject_add_internal [1]. This
happens when multiple HCI_EV_SYNC_CONN_COMPLETE event packets with
status 0 are sent for the same HCI connection. This causes us to
register the device more than once which corrupts the kset list.

As this is forbidden behavior, we add a check for whether we're
trying to process the same HCI_EV_SYNC_CONN_COMPLETE event multiple
times for one connection. If that's the case, the event is invalid, so
we report an error that the device is misbehaving, and ignore the
packet.

Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [1]
Reported-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
Tested-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
---

v1 -> v2:
- Added more comments to explain the reasoning behind the new check, and
a bt_dev_err message upon detecting the invalid event. As suggested by
Marcel Holtmann.

 net/bluetooth/hci_event.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 016b2999f219..a6df4f9d2c23 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4373,6 +4373,22 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev,
 
 	switch (ev->status) {
 	case 0x00:
+		/* The synchronous connection complete event should only be
+		 * sent once per new connection. Receiving a successful
+		 * complete event when the connection status is already
+		 * BT_CONNECTED means that the device is misbehaving and sent
+		 * multiple complete event packets for the same new connection.
+		 *
+		 * Registering the device more than once can corrupt kernel
+		 * memory, hence upon detecting this invalid event, we report
+		 * an error and ignore the packet.
+		 */
+		if (conn->state == BT_CONNECTED) {
+			bt_dev_err(hdev,
+				   "received multiple HCI_EV_SYNC_CONN_COMPLETE events with status 0 for conn %p",
+				   conn);
+			goto unlock;
+		}
 		conn->handle = __le16_to_cpu(ev->handle);
 		conn->state  = BT_CONNECTED;
 		conn->type   = ev->link_type;
-- 
2.25.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* RE: [v2] Bluetooth: skip invalid hci_sync_conn_complete_evt
  2021-07-28  7:51 [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt Desmond Cheong Zhi Xi
@ 2021-07-28  9:07 ` bluez.test.bot
  2021-07-29 11:38 ` [PATCH v2] " Marcel Holtmann
  1 sibling, 0 replies; 3+ messages in thread
From: bluez.test.bot @ 2021-07-28  9:07 UTC (permalink / raw)
  To: linux-bluetooth, desmondcheongzx

[-- Attachment #1: Type: text/plain, Size: 2727 bytes --]

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=522503

---Test result---

Test Summary:
CheckPatch                    PASS      0.47 seconds
GitLint                       PASS      0.11 seconds
BuildKernel                   PASS      513.00 seconds
TestRunner: Setup             PASS      323.25 seconds
TestRunner: l2cap-tester      PASS      2.48 seconds
TestRunner: bnep-tester       PASS      1.92 seconds
TestRunner: mgmt-tester       PASS      28.95 seconds
TestRunner: rfcomm-tester     PASS      1.99 seconds
TestRunner: sco-tester        PASS      1.93 seconds
TestRunner: smp-tester        FAIL      2.00 seconds
TestRunner: userchan-tester   PASS      1.94 seconds

Details
##############################
Test: CheckPatch - PASS - 0.47 seconds
Run checkpatch.pl script with rule in .checkpatch.conf


##############################
Test: GitLint - PASS - 0.11 seconds
Run gitlint with rule in .gitlint


##############################
Test: BuildKernel - PASS - 513.00 seconds
Build Kernel with minimal configuration supports Bluetooth


##############################
Test: TestRunner: Setup - PASS - 323.25 seconds
Setup environment for running Test Runner


##############################
Test: TestRunner: l2cap-tester - PASS - 2.48 seconds
Run test-runner with l2cap-tester
Total: 40, Passed: 40 (100.0%), Failed: 0, Not Run: 0

##############################
Test: TestRunner: bnep-tester - PASS - 1.92 seconds
Run test-runner with bnep-tester
Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0

##############################
Test: TestRunner: mgmt-tester - PASS - 28.95 seconds
Run test-runner with mgmt-tester
Total: 448, Passed: 445 (99.3%), Failed: 0, Not Run: 3

##############################
Test: TestRunner: rfcomm-tester - PASS - 1.99 seconds
Run test-runner with rfcomm-tester
Total: 9, Passed: 9 (100.0%), Failed: 0, Not Run: 0

##############################
Test: TestRunner: sco-tester - PASS - 1.93 seconds
Run test-runner with sco-tester
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0

##############################
Test: TestRunner: smp-tester - FAIL - 2.00 seconds
Run test-runner with smp-tester
Total: 8, Passed: 7 (87.5%), Failed: 1, Not Run: 0

Failed Test Cases
SMP Client - SC Request 2                            Failed       0.022 seconds

##############################
Test: TestRunner: userchan-tester - PASS - 1.94 seconds
Run test-runner with userchan-tester
Total: 3, Passed: 3 (100.0%), Failed: 0, Not Run: 0



---
Regards,
Linux Bluetooth


[-- Attachment #2: l2cap-tester.log --]
[-- Type: application/octet-stream, Size: 44386 bytes --]

[-- Attachment #3: bnep-tester.log --]
[-- Type: application/octet-stream, Size: 3593 bytes --]

[-- Attachment #4: mgmt-tester.log --]
[-- Type: application/octet-stream, Size: 616861 bytes --]

[-- Attachment #5: rfcomm-tester.log --]
[-- Type: application/octet-stream, Size: 11712 bytes --]

[-- Attachment #6: sco-tester.log --]
[-- Type: application/octet-stream, Size: 9947 bytes --]

[-- Attachment #7: smp-tester.log --]
[-- Type: application/octet-stream, Size: 11741 bytes --]

[-- Attachment #8: userchan-tester.log --]
[-- Type: application/octet-stream, Size: 5490 bytes --]

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt
  2021-07-28  7:51 [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt Desmond Cheong Zhi Xi
  2021-07-28  9:07 ` [v2] " bluez.test.bot
@ 2021-07-29 11:38 ` Marcel Holtmann
  1 sibling, 0 replies; 3+ messages in thread
From: Marcel Holtmann @ 2021-07-29 11:38 UTC (permalink / raw)
  To: Desmond Cheong Zhi Xi
  Cc: Johan Hedberg, Luiz Augusto von Dentz, David S. Miller,
	Jakub Kicinski, linux-bluetooth, open list:NETWORKING [GENERAL],
	open list, skhan, Greg Kroah-Hartman, linux-kernel-mentees,
	syzbot+66264bf2fd0476be7e6c

Hi Desmond,

> Syzbot reported a corrupted list in kobject_add_internal [1]. This
> happens when multiple HCI_EV_SYNC_CONN_COMPLETE event packets with
> status 0 are sent for the same HCI connection. This causes us to
> register the device more than once which corrupts the kset list.
> 
> As this is forbidden behavior, we add a check for whether we're
> trying to process the same HCI_EV_SYNC_CONN_COMPLETE event multiple
> times for one connection. If that's the case, the event is invalid, so
> we report an error that the device is misbehaving, and ignore the
> packet.
> 
> Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [1]
> Reported-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
> Tested-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
> Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
> ---
> 
> v1 -> v2:
> - Added more comments to explain the reasoning behind the new check, and
> a bt_dev_err message upon detecting the invalid event. As suggested by
> Marcel Holtmann.
> 
> net/bluetooth/hci_event.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)

I shortened the error message and then applied your patch to bluetooth-next tree.

Regards

Marcel


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-07-29 11:38 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-28  7:51 [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt Desmond Cheong Zhi Xi
2021-07-28  9:07 ` [v2] " bluez.test.bot
2021-07-29 11:38 ` [PATCH v2] " Marcel Holtmann

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).