[PATCH v2] Bluetooth: hci_event: Detect if HCI_EV_NUM_COMP_PKTS is unbalanced

[PATCH v2] Bluetooth: hci_event: Detect if HCI_EV_NUM_COMP_PKTS is unbalanced

[Luiz Augusto von Dentz]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This attempts to detect if HCI_EV_NUM_COMP_PKTS contain an unbalanced
(more than currently considered outstanding) number of packets otherwise
it could cause the hcon->sent to underflow and loop around breaking the
tracking of the outstanding packets pending acknowledgment.

Fixes: f42809185896 ("Bluetooth: Simplify num_comp_pkts_evt function")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/hci_event.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 512041c68062..dc946c5b59d8 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4414,7 +4414,17 @@ static void hci_num_comp_pkts_evt(struct hci_dev *hdev, void *data,
 		if (!conn)
 			continue;
 
-		conn->sent -= count;
+		/* Check if there is really enough packets outstanding before
+		 * attempting to decrease the sent counter otherwise it could
+		 * underflow..
+		 */
+		if (conn->sent >= count) {
+			conn->sent -= count;
+		} else {
+			bt_dev_warn(hdev, "hcon %p sent %u < count %u",
+				    conn, conn->sent, count);
+			conn->sent = 0;
+		}
 
 		for (i = 0; i < count; ++i)
 			hci_conn_tx_dequeue(conn);
-- 
2.50.1

RE: [v2] Bluetooth: hci_event: Detect if HCI_EV_NUM_COMP_PKTS is unbalanced

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2497 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=994058

---Test result---

Test Summary:
CheckPatch                    PENDING   0.43 seconds
GitLint                       PENDING   0.40 seconds
SubjectPrefix                 PASS      0.06 seconds
BuildKernel                   PASS      24.12 seconds
CheckAllWarning               PASS      26.63 seconds
CheckSparse                   WARNING   29.93 seconds
BuildKernel32                 PASS      24.29 seconds
TestRunnerSetup               PASS      485.93 seconds
TestRunner_l2cap-tester       PASS      25.76 seconds
TestRunner_iso-tester         PASS      41.22 seconds
TestRunner_bnep-tester        PASS      6.21 seconds
TestRunner_mgmt-tester        FAIL      131.90 seconds
TestRunner_rfcomm-tester      PASS      9.67 seconds
TestRunner_sco-tester         PASS      15.02 seconds
TestRunner_ioctl-tester       PASS      10.43 seconds
TestRunner_mesh-tester        FAIL      11.63 seconds
TestRunner_smp-tester         PASS      8.88 seconds
TestRunner_userchan-tester    PASS      6.50 seconds
IncrementalBuild              PENDING   1.01 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: CheckSparse - WARNING
Desc: Run sparse tool with linux kernel
Output:
net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h):
##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 490, Passed: 485 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.112 seconds
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    1.893 seconds
Mesh - Send cancel - 2                               Timed out    1.997 seconds
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH v2] Bluetooth: hci_event: Detect if HCI_EV_NUM_COMP_PKTS is unbalanced

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Thu, 21 Aug 2025 09:47:14 -0400 you wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> 
> This attempts to detect if HCI_EV_NUM_COMP_PKTS contain an unbalanced
> (more than currently considered outstanding) number of packets otherwise
> it could cause the hcon->sent to underflow and loop around breaking the
> tracking of the outstanding packets pending acknowledgment.
> 
> [...]

Here is the summary with links:
  - [v2] Bluetooth: hci_event: Detect if HCI_EV_NUM_COMP_PKTS is unbalanced
    https://git.kernel.org/bluetooth/bluetooth-next/c/05be312ba55c

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html