From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1D15C37646D; Tue, 17 Feb 2026 20:44:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771361052; cv=none; b=o0ennQk4ZbnuDoOoNACVr8VlVgNJW3sP7PLCx2uVooinDEic0xd6i2VRNgtqO/f0iLBHYNtSp0FsvjLqF6DroStNf3OAgpwnnE4DggBstuL3eT/iRbRmcCdlxkxQVTKTlPj7qd8tSgWMCQsqc0RHxFio6OUlbANEImzCvx1MuM0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771361052; c=relaxed/simple; bh=5rFTq17RlpImuR7yFVM4Ls14jBc75K59sjiLIaykXJQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bTqmodCmP/o0j4vDo+gIrS31myxHEooemvjDx7biZjt0ijILTVEAaQHu8WaoIkNMztC6cKaaAS1ns7JoepwKPjTc8qLHJtu20alwIza4MHRS1JGxmbqjKzEMbH4fCmXOagEqE8sK7EWslzz4xZRaFRwsYJvuKE/+7t3RkQldm+Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Bt93NvJC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Bt93NvJC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2438CC4CEF7; Tue, 17 Feb 2026 20:44:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771361051; bh=5rFTq17RlpImuR7yFVM4Ls14jBc75K59sjiLIaykXJQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bt93NvJCrtXN6d2BDP9JYJZj0RSDiOW0Iw9c3Jg7vm1CNouFHShgVa70lqZjwmwGU U+5ymTEr3Kl4XFiL9NH2Ea7uNgkU05+Y5nQYhwv2tUy2NxYo1j90dhT6l0NQCjVi3+ 4R+f9TcML0BIcmKtHhLc/00fzHRUGO6AF73djx7g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gui-Dong Han , Ioana Ciornei , "Christophe Leroy (CS GROUP)" , Sasha Levin Subject: [PATCH 5.15 26/39] bus: fsl-mc: fix use-after-free in driver_override_show() Date: Tue, 17 Feb 2026 21:31:35 +0100 Message-ID: <20260217200003.939571930@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260217200002.929083107@linuxfoundation.org> References: <20260217200002.929083107@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gui-Dong Han [ Upstream commit 148891e95014b5dc5878acefa57f1940c281c431 ] The driver_override_show() function reads the driver_override string without holding the device_lock. However, driver_override_store() uses driver_set_override(), which modifies and frees the string while holding the device_lock. This can result in a concurrent use-after-free if the string is freed by the store function while being read by the show function. Fix this by holding the device_lock around the read operation. Fixes: 1f86a00c1159 ("bus/fsl-mc: add support for 'driver_override' in the mc-bus") Cc: stable@vger.kernel.org Signed-off-by: Gui-Dong Han Reviewed-by: Ioana Ciornei Link: https://lore.kernel.org/r/20251202174438.12658-1-hanguidong02@gmail.com Signed-off-by: Christophe Leroy (CS GROUP) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/bus/fsl-mc/fsl-mc-bus.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -199,8 +199,12 @@ static ssize_t driver_override_show(stru struct device_attribute *attr, char *buf) { struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); + ssize_t len; - return sysfs_emit(buf, "%s\n", mc_dev->driver_override); + device_lock(dev); + len = sysfs_emit(buf, "%s\n", mc_dev->driver_override); + device_unlock(dev); + return len; } static DEVICE_ATTR_RW(driver_override);