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 4B13F43CE76 for ; Wed, 26 Aug 2026 13:47:21 +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=1787752043; cv=none; b=O/JY84znlc3tlm3fqKdGsIyPCErmU34dqwpG8xtF7UKrP2e7/wcB46hei+6/ZtglIeGWcn+M1ndACYHVljvgDt54ECwu1uunFT4zDFhet1vVwb7KWFJ1OVfL6NjxPTFCHjBxrLY0jb39F4V2cotKFgbnfoeEr+LZEzYOfB5/UMQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787752043; c=relaxed/simple; bh=D+/pzhpch6/SKPu+P++wIgwOegNFS3aHHk1MutxllQ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pmejaPBWFyV077BCBoasq+Tf9H5GZ7E4MtebyedoOyPm5AaUnes9qQMloEzMVt3UNAwftDD+gR4406F4hKNdmSdQL6ps14IfqPwesvXjTBGrLYPGt6jeelTPcLgfcRfJ7HokJwmxFGjWo3QCGUl8phNgoonM2jZXY03dFB9KGtw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XMTuMzfM; 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="XMTuMzfM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAE251F00A3E; Wed, 26 Aug 2026 13:47:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787752040; bh=G0W4RsLOVDkQJgAaZcSDGP0SKS+yZ6ZewuneX5I0Mbo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XMTuMzfMEnkYje3/F/bExGOaLjhJ+zUTOXyQK9zG1My5vbKlF0PVhtV6FuxOnM41p LAvrcb0VvYXmn//76ENJZEFEZ1nM12kzDpaKN5r7cTZyLw4ZwAbVyKZ1igGgSLem7F N7WrNugBE58dSwwB/sqPlInAqQ2X7NIRTS+t2Qys35Id0h2vis8y+4Dbt7R0EfX7nK 7WucGMC3dCT/WqxuEcynFWcRiIzYiu0Ra4QOgZJ4T1q3EA4svJQsAnnqEcvEWBv6Ig wsbyjQj4oegMcQjDJq2JNecdjmMW6UJiNXx829/MJLpDPEW+hYlb60xs+9UYcnphy0 iv+xzP3mTtJHw== From: Sasha Levin To: stable@vger.kernel.org Cc: Baul Lee , Federico Kirschbaum , Jiri Kosina , Sasha Levin Subject: [PATCH 6.12.y 4/4] HID: pidff: fix OOB write when hid->inputs is empty Date: Wed, 26 Aug 2026 09:47:15 -0400 Message-ID: <20260826134715.3968449-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260826134715.3968449-1-sashal@kernel.org> References: <2026082517-petroleum-anaerobic-3fd3@gregkh> <20260826134715.3968449-1-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 72ed11e054665..751570de7f52a 100644 --- a/drivers/hid/usbhid/hid-pidff.c +++ b/drivers/hid/usbhid/hid-pidff.c @@ -1405,13 +1405,20 @@ 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