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 F0E4B42F6FA; Thu, 16 Jul 2026 14:29:35 +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=1784212177; cv=none; b=XZ/3Tl42BDKWvSjbA6E14vokMwFu6vJKFk3K5icelODXES/E7pM6Y2meAcP59rczB1ZR58nsGsLTlJeYgYrwsMhNbfo14NsesUMR5k5p5ms2AXbqXVS+qhMDA269hJOO6A66vXgbii/NSzVaMn6a40hBnahtdHlhiyQQmn6IX3s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212177; c=relaxed/simple; bh=MxtEEeMBUQskrK4CbJuKjm6gPWX4zovh/NvX0TqKE0E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jLsFjs90a85pzyC1EaUVjPm6RWV6yhqZazu60u7FUECF69kNPFteMAtM3cho9Q2wcxHb1wlyNgxo8hSvWA8URqqyw+GBQAraFF/TotwxPycMqHdgTYfIXO9iT0Tv2RldhHlfqahiCI3wQ63YYMqYbcwb5TVw+7Lc0tdiOg8dqT4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=uD86B22K; 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="uD86B22K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 623A31F000E9; Thu, 16 Jul 2026 14:29:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784212175; bh=U1BbS6IjYlM3Q2d6USXi6S02DPJuLcjDKBGghgEZpr4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=uD86B22K6kiWxK7oAGWO7SUJ6vC/1z30i34mBe4embg7zDmpdJs+sNz6CGZtsv6dg exgGrvlIZLM1Gjyuzwc1xdO/YDU6h+ByGCrOkXufFt2BdQQT8NG+wdZDcGhK80910I gZAzdRRhBnJZOOA5MRVKoijDfieOnxE/CgOCqbUk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Xu Rao Subject: [PATCH 6.12 227/349] usb: gadget: f_printer: take kref only for successful open Date: Thu, 16 Jul 2026 15:32:41 +0200 Message-ID: <20260716133038.442212885@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xu Rao commit 30adce93d5c4a5a1ec29d9249e3fdfcc391d406b upstream. printer_open() returns -EBUSY when the character device is already open, but it increments dev->kref regardless of the return value. VFS does not call ->release() for a failed open, so every rejected second open permanently leaks one reference. Move kref_get() into the successful-open branch. Fixes: e8d5f92b8d30 ("usb: gadget: function: printer: fix use-after-free in __lock_acquire") Cc: stable Signed-off-by: Xu Rao Link: https://patch.msgid.link/80295742B820DA9B+20260626064617.4090626-1-raoxu@uniontech.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_printer.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/usb/gadget/function/f_printer.c +++ b/drivers/usb/gadget/function/f_printer.c @@ -363,12 +363,11 @@ printer_open(struct inode *inode, struct ret = 0; /* Change the printer status to show that it's on-line. */ dev->printer_status |= PRINTER_SELECTED; + kref_get(&dev->kref); } spin_unlock_irqrestore(&dev->lock, flags); - kref_get(&dev->kref); - return ret; }