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 4DD05277818 for ; Sun, 19 Jul 2026 14:16:36 +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=1784470597; cv=none; b=KSQV02gMNur/s53+hsNfDeXlfCTS+wnTF6y8sS/BTSrP482fGBIqxIBjJkBc4eWy1nmhDv2tZ8rrtgyb+E+KTOHhT+H9o1UtcujMYDH44aNNRgQc4bCm5XSeHBAgEEgBV17YNtSfMgPgPWLm5RNA5u2vLWisBFxabRkcGj4Dwg0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784470597; c=relaxed/simple; bh=1H7ZTeS6jkKVPK1zkkqD+EGX9mtvMf9/RAjVG2cBM0g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pnhVJ0pmBbXHopBUcnBfXW545/tks5SZDBzOZrt+YdWVCgj5PCMUPs/WUqNr8t5VqT+sdxiHrQcfPymSX3n8218usl0Z6aVhCBTg2DZ5iFbaQYIqfJk+Mk94UHzabjqD5mIAWSe8Jhsa87zrkASyBWB4F3+tAiZhUfdTXU9pMos= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bHSJK8ub; 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="bHSJK8ub" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7385B1F00A3D; Sun, 19 Jul 2026 14:16:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784470596; bh=Pd/3OVTiBG2e9czHFOg6FSliqt1meumjK0aBX/unJqk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bHSJK8ubfEKqL+1rcNlqpQ5m9E+mKVNU1B8Ovl/vyIIuNErn2YqKMcJGvfPIH7fra WDBeI+vIzkESxIWJDN2Zo0qWmbO6nPLaidpmOci2vxncZrjT1eibWD9CxhNcjx2E1B L5GpPhGlwh/4geZ1EXBQsJVMKQSwvFMWHG+MSt3bqJ8/MtdVKHOhEBln+GP10G8olY IGj/nX/RUrVt7JCgVC6OmK1yi51X/MvPm+3+ciXH2EVeP1aUwmgeYRRRLVQZM+uR74 RKAge2Gt2t5JTOGJOtYZiTTZ8qSol7Vyf5jbqNE774n0trqmy72rA7Iqe3DfqeRMoV vm1pKEoQb4MiQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Xu Rao , stable , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.1.y 2/2] usb: gadget: f_printer: take kref only for successful open Date: Sun, 19 Jul 2026 10:16:32 -0400 Message-ID: <20260719141632.4057531-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260719141632.4057531-1-sashal@kernel.org> References: <2026071412-chop-overreach-6861@gregkh> <20260719141632.4057531-1-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: Xu Rao [ Upstream commit 30adce93d5c4a5a1ec29d9249e3fdfcc391d406b ] 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 Signed-off-by: Sasha Levin --- drivers/usb/gadget/function/f_printer.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c index 6f995b87aa5743..fe87f551b8f30e 100644 --- a/drivers/usb/gadget/function/f_printer.c +++ b/drivers/usb/gadget/function/f_printer.c @@ -360,12 +360,11 @@ printer_open(struct inode *inode, struct file *fd) 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; } -- 2.53.0