From nobody Fri Jul 24 21:30:17 2026 Received: from mail-m49198.qiye.163.com (mail-m49198.qiye.163.com [45.254.49.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3BA64432E97; Fri, 24 Jul 2026 15:13:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.254.49.198 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784906017; cv=none; b=D8U1AIy7gjFJ8ubzCvBUuwO3caua9edc1uacbUPjCUmj3OK4GcmafAkoUkYlTItH+tXTBlQqp5Yb/KHQ8LIbZJTxYPU0BhzXZzSSMS7bbYDKK+qkXNPDF+hpq3rQ0uP4eYGHbpKo0UuAeRxQbyuOoV5eMHzzoNOt/RQS7006ujo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784906017; c=relaxed/simple; bh=HPUpxtCxpINYLEfuU25Z3pvyKyTLddcc+SYmp5XtriM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=eCFMvuNjF/TohkKrENeSROKHW4jaOsxHFWnIT+x52XyGwL0dcKa9I4vid6rarA74EjO0H21TZvwaOhv4NNyds72XSkmw0T3QXvZnIUz1Gu+fxq9arqgoKC5emCuC9EgzKGOb3WVkRuwEdDml92d13kchjGY8xUgJNuPBiJ8Y/6c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=seu.edu.cn; spf=pass smtp.mailfrom=seu.edu.cn; dkim=pass (1024-bit key) header.d=seu.edu.cn header.i=@seu.edu.cn header.b=cpuyvyEI; arc=none smtp.client-ip=45.254.49.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=seu.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=seu.edu.cn Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=seu.edu.cn header.i=@seu.edu.cn header.b="cpuyvyEI" Received: from ShouCheng-Lab.localdomain (unknown [218.2.107.243]) by smtp.qiye.163.com (Hmail) with ESMTP id 477b224c2; Fri, 24 Jul 2026 23:13:25 +0800 (GMT+08:00) From: Jiancheng Huang To: Jiri Kosina , Benjamin Tissoires Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] HID: lg4ff: validate report length before fixed offsets Date: Fri, 24 Jul 2026 23:13:17 +0800 Message-ID: <20260724151317.1419574-1-jchuang@seu.edu.cn> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-HM-Tid: 0a9f94b03a2f03a2kunm63b44f9445778 X-HM-MType: 10 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVlCTk5LVh5PSh1DSk5MSE0ZGFYeHw 5VEwETFhoSFyQUDg9ZV1kYEgtZQVlJSkNVSVVKS0xVSU9IWVdZFhoPEhUdFFlBWU9LSFVKS0hKTk xOVUpLS1VKQktLWQY+ DKIM-Signature: a=rsa-sha256; b=cpuyvyEIGOt8mYGF/uouhrbjJGm4F5/ciu1ojaUnOYdxj4ZS5iPnLzxTTezhQbOoDUhLySSkhRsOEHXlKXuKX015W6N0DNM5ALcirY0pJ9j/UXKX3VLwkxwCHlpwN74iI+U8w3mdQLgVLmh1poXsFK23HGa4YNKWhFz7K2aimKI=; s=default; c=relaxed/relaxed; d=seu.edu.cn; v=1; bh=mfjyetoRQcuQJG/GPiFFBwofwgVMAPECP+RHTGK4/Tg=; h=date:mime-version:subject:message-id:from; Content-Type: text/plain; charset="utf-8" lg4ff_raw_event() rewrites fixed report offsets when combined pedals are enabled. It currently assumes that each product report contains every source and destination byte used by the rewrite. Return without rewriting a short report before each product-specific access. Apply the same bound to the computed offset path. Fixes: c832f86effbc ("HID: hid-logitech: Add combined pedal support Logitec= h wheels") Signed-off-by: Jiancheng Huang Assisted-by: Codex:gpt-5.6-luna --- Changes in v2: - Add the relevant public mailing lists to Cc; no source changes. Evidence (v7.2-rc4 KUnit/KASAN oracle under bounded QEMU): Source: confirmed/hid_lg4ff_short_report_oob_raw_excerpt.log [ 2.638792] KTAP version 1 [ 2.638888] 1..1 [ 2.641100] KTAP version 1 [ 2.641235] # Subtest: hid-lg4ff-exploration [ 2.641784] # module: hid_logitech [ 2.641962] 1..1 [ 2.644581] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ 2.645008] BUG: KASAN: slab-out-of-bounds in lg4ff_raw_event+0x2fd/0x410 [ 2.645369] Read of size 1 at addr ffff88800229fc63 by task kunit_try_ca= tch/67 [ 2.645369]=20 [ 2.645369] CPU: 1 UID: 0 PID: 67 Comm: kunit_try_catch Tainted: G = N 7.2.0-rc4-dirty #3 PREEMPT(full)=20 [ 2.645369] Tainted: [N]=3DTEST [ 2.645369] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_= caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 2.645369] Call Trace: [ 2.645369] [ 2.645369] dump_stack_lvl+0x53/0x70 [ 2.645369] print_report+0xd0/0x630 [ 2.645369] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 2.645369] ? lg4ff_raw_event+0x2fd/0x410 [ 2.645369] kasan_report+0xe5/0x120 [ 2.645369] ? lg4ff_raw_event+0x2fd/0x410 [ 2.645369] lg4ff_raw_event+0x2fd/0x410 [ 2.645369] lg4ff_short_report_oob_test+0x14e/0x250 drivers/hid/hid-lg4ff.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c index e901fdb7d..62f99a932 100644 --- a/drivers/hid/hid-lg4ff.c +++ b/drivers/hid/hid-lg4ff.c @@ -336,6 +336,8 @@ int lg4ff_raw_event(struct hid_device *hdev, struct hid= _report *report, if (entry->wdata.combine) { switch (entry->wdata.product_id) { case USB_DEVICE_ID_LOGITECH_WHEEL: + if (size < 7) + return 0; rd[5] =3D rd[3]; rd[6] =3D 0x7F; return 1; @@ -343,10 +345,14 @@ int lg4ff_raw_event(struct hid_device *hdev, struct h= id_report *report, case USB_DEVICE_ID_LOGITECH_WINGMAN_FFG: case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL: case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2: + if (size < 6) + return 0; rd[4] =3D rd[3]; rd[5] =3D 0x7F; return 1; case USB_DEVICE_ID_LOGITECH_DFP_WHEEL: + if (size < 7) + return 0; rd[5] =3D rd[4]; rd[6] =3D 0x7F; return 1; @@ -366,6 +372,8 @@ int lg4ff_raw_event(struct hid_device *hdev, struct hid= _report *report, } =20 /* Compute a combined axis when wheel does not supply it */ + if (size <=3D offset + 1) + return 0; rd[offset] =3D (0xFF + rd[offset] - rd[offset+1]) >> 1; rd[offset+1] =3D 0x7F; return 1; --=20 2.43.0