From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4EB103FFACC for ; Wed, 26 Aug 2026 17:14:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787764490; cv=none; b=LqtN306TZcumE+vXQTtotTQ/7mNLe+icuumVBLKEpk5SISJznMSoAHtjTXqGbTVHAlbPDFIxy9ZsrrvMoHFLgJQAiJr0RuxGkoykd7fqDRGcUGKkfg+1oDW3rCL1GAcQgXyiccBdEgrWOMpDyWZXqH2YDJ03flKqHTUMfb3MFBs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787764490; c=relaxed/simple; bh=M8+7JWOdEYT95B5KxsxXeqCq2g+xERyT47Nv0fcLi/A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=W/KlrdSpeGeL/aaZQaNtvZtVkfYGXuOUANQu/9slJrH3wm77NSjZPq3S/N/eCfU+z/gPktkDQjvW6H/SeUc3/pzkv33BNYdN8sB7FhlPW8O8rN/OnoKEuu6AI2KRlif5+nro8XP0FKxjRs1dqU79f/bhEr2iIeS8u9B1q55If9E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M1kOm3mJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M1kOm3mJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D76A51F0155A; Wed, 26 Aug 2026 17:14:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787764452; bh=2813CSk61E8k4CB1jjOBMi0MfnvnpGVUW9OHBP5TwZo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=M1kOm3mJWDBX5+YOPWPIEsr8x9j+lyDOiyfFQrmyiEZj10/l1Fc9WG6RRe89cNkYO d1kmTvPAx1EaE+5YtFeWFnh1uXm2R8Hb7FsKP6LJ0f4umGTsqLjeu3yYqPIR0qUirx gZJ95ppZbuYDMb199FOyudScIKqZa7NJW7cLzd0g+oLCS9BQpT8tKjF77apiKFgFLL 1skNo/7QLxXPcLPL2pwZOQvNH9+8FgeL+GlKHf+voNwvSd6KTJwDOmOmJwg02mSlwQ GyXnIl9IlWC5R0Jn5UyL33dIsYXLbMoRMPYs0zE983uoyM4SqGv5Nkof8HsPLCSan2 A5wFuXXzPHv+w== From: Sasha Levin To: stable@vger.kernel.org Cc: Baul Lee , Federico Kirschbaum , Jiri Kosina , Sasha Levin Subject: [PATCH 6.6.y 3/3] HID: pidff: fix OOB write when hid->inputs is empty Date: Wed, 26 Aug 2026 13:14:08 -0400 Message-ID: <20260826171408.2245886-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260826171408.2245886-1-sashal@kernel.org> References: <2026082518-countless-imply-6af9@gregkh> <20260826171408.2245886-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Baul Lee [ Upstream commit 67bb1074e3d2d12fa059a9cc707e89398a4e4704 ] hid_pidff_init_with_quirks() derives its input_dev from list_entry(hid->inputs.next, struct hid_input, list) without first checking that hid->inputs is non-empty. The list member of struct hid_input is at offset 0, so on an empty list list_entry() yields &hid->inputs itself and the following hidinput->input load reads an unrelated member of struct hid_device. dev is then a type-confused pointer, and force-feedback init writes through it: each set_bit(FF_*, dev->ffbit) stores 8 bytes at dev + 192, past the end of the object dev actually aliases, and input_ff_create() adds further writes of a heap pointer and two function pointers. Until hid-universal-pidff the only caller was hid_pidff_init() from usbhid, which runs under HID_CLAIMED_INPUT and therefore always has at least one hid_input. universal_pidff_probe() starts the device with HID_CONNECT_DEFAULT & ~HID_CONNECT_FF and then calls hid_pidff_init_with_quirks() directly whenever the descriptor carries a PID usage page, bypassing that gate. A report descriptor whose only application collection is on HID_UP_PID leaves hid->inputs empty while hid_connect() still succeeds through the hidraw claim, so probe reaches the unguarded list_entry(). The write happens in the USB probe path, on the hotplug workqueue, so plugging in a malicious device is enough to trigger it; no attacker software and no logged-in user are required. KASAN reports an 8-byte out-of-bounds write in hid_pidff_init_with_quirks() reached from universal_pidff_probe(). Check for an empty list before deriving dev and return -ENODEV, as the other HID force-feedback drivers already do. universal_pidff_probe() propagates the error and unwinds. Discovered by XBOW, triaged by Baul Lee Fixes: f06bf8d94fff ("HID: Add hid-universal-pidff driver and supported device ids") Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/usbhid/hid-pidff.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/hid/usbhid/hid-pidff.c b/drivers/hid/usbhid/hid-pidff.c index ad0636ca71776..cf03400a47381 100644 --- a/drivers/hid/usbhid/hid-pidff.c +++ b/drivers/hid/usbhid/hid-pidff.c @@ -1298,13 +1298,20 @@ static int pidff_check_autocenter(struct pidff_device *pidff, int hid_pidff_init_with_quirks(struct hid_device *hid, __u32 initial_quirks) { struct pidff_device *pidff; - struct hid_input *hidinput = - list_entry(hid->inputs.next, struct hid_input, list); - struct input_dev *dev = hidinput->input; + struct hid_input *hidinput; + struct input_dev *dev; struct ff_device *ff; int max_effects; int error; + if (list_empty(&hid->inputs)) { + hid_err(hid, "no inputs found\n"); + return -ENODEV; + } + + hidinput = list_first_entry(&hid->inputs, struct hid_input, list); + dev = hidinput->input; + hid_dbg(hid, "starting pid init\n"); if (list_empty(&hid->report_enum[HID_OUTPUT_REPORT].report_list)) { -- 2.53.0