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 00FF22C21F7; Sat, 12 Sep 2026 09:40:13 +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=1789206014; cv=none; b=K4DplIYwQVGyMHnYOVJALL0dr3wQpSQKrcIUikV2beKJ2v7+ssuD7dvDWRzwLAFHDn1y2vEkaP9A3EHLrSKLFacrGQFntDkRc3LEYbxoTswgTeJdZE47UHSDYOfa/CukpCQgttzVCgO5Y8OemuECakYGR9N1yRYdnt+M9rW9s+A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789206014; c=relaxed/simple; bh=ILBn/zIsjMUStIQfuiiG2I1t0i7dKO2cPr8xQ9sL4jE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rq1N4kJNnD5gPOnsEl5pVFyfMR0AOmbXh4QvBW48QGFMe2gWlnEFrao6/ElYkMn5jlk8FbUpQ46qhmu24ALy62jczO/MdbW2lSVnmqOq0olfO/bWaqabdNQ//TlFH+0WnM4AVtKYNYb1v2YtbmneU0iBqFkUtTzd9XWvvNRvOXs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vzqSfUVh; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vzqSfUVh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7BF51F000FF; Sat, 12 Sep 2026 09:40:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789206012; bh=FRkkB3pdhct4yz6qvpDdr+9/7ksbCu6Nl4lzCjF7shs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vzqSfUVhHLTOq4vH7b0LK4nEXH9wWNkSt9TH7DvjbQR5XPAD3aJGA/gpvL8ljerOA BmLPOI5duyZc7Ips50U9jdHTED7XdFMbAfCUmFNHmck0dRT+LFeNk2QYUiO5MqfXdd KveaXQ6OtRjmXezCYFSoEjY4qNTF3T2iHGOn6iR8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+9eebf5f6544c5e873858@syzkaller.appspotmail.com, Philipp Weber , Jiri Kosina , Sasha Levin Subject: [PATCH 6.18 0119/1518] HID: core: quiesce input in hid_hw_stop() to prevent use-after-free Date: Sat, 12 Sep 2026 08:38:08 +0200 Message-ID: <20260912065626.181611894@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Philipp Weber [ Upstream commit a4bc41504690b7d7064931909874f5b98cd148b6 ] A driver's probe calls hid_device_io_start() to enable input delivery, then fails at a later initialization step and unwinds via hid_hw_stop(). The unwind frees struct hidraw via hidraw_disconnect() while in-flight HID reports may still be running on another CPU, dereferencing the freed object through hidraw_report_event(). syzbot reports the resulting use-after-free for the corsair-psu HID driver. Edward Adam Davis posted a per-driver fix for corsair-psu that adds an explicit hid_device_io_stop() before hid_hw_stop() in the probe error path ("hwmon: prevent packets from going to driver for probe", 2026-04-28). Auditing the tree shows 15 drivers call hid_device_io_start(); 7 also call hid_device_io_stop() and 8 do not: drivers calling hid_device_io_start() without a matching hid_device_io_stop() before hid_hw_stop(): drivers/hwmon/corsair-psu.c (fix posted by Edward) drivers/hwmon/corsair-cpro.c drivers/hwmon/nzxt-kraken3.c drivers/hwmon/nzxt-smart2.c drivers/hwmon/gigabyte_waterforce.c drivers/hid/hid-logitech-dj.c drivers/hid/hid-nintendo.c drivers/hid/hid-mcp2221.c Roughly half of all callers of the API are exposed. Centralize the quiesce in hid_hw_stop() so callers do not have to remember the matching stop: if a driver has left hdev->io_started true on entry, call hid_device_io_stop() before hid_disconnect(). For the 7 drivers that already call hid_device_io_stop() correctly, hdev->io_started is false on entry, the guard short-circuits, and behavior is unchanged. No Fixes: tag because the affected drivers gained their hid_device_io_start() calls independently over years; the bug is a class-wide API misuse rather than a regression from one commit. Reported-by: syzbot+9eebf5f6544c5e873858@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9eebf5f6544c5e873858 Signed-off-by: Philipp Weber Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/hid-core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 7f442a2798d8f..55990d17c5669 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2450,9 +2450,16 @@ EXPORT_SYMBOL_GPL(hid_hw_start); * * This is usually called from remove function or from probe when something * failed and hid_hw_start was called already. + * + * If the caller enabled HID input via hid_device_io_start() and is unwinding + * without an explicit hid_device_io_stop(), quiesce input first so that + * in-flight reports cannot reach handlers (e.g. hidraw_report_event) whose + * backing objects hid_disconnect() is about to free. */ void hid_hw_stop(struct hid_device *hdev) { + if (hdev->io_started) + hid_device_io_stop(hdev); hid_disconnect(hdev); hdev->ll_driver->stop(hdev); } -- 2.53.0