* [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 related [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 --]
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[-- Attachment #6: sco-tester.log --]
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[-- Attachment #8: userchan-tester.log --]
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^ 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
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2021-07-28 9:07 ` [v2] " bluez.test.bot
2021-07-29 11:38 ` [PATCH v2] " Marcel Holtmann
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