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 E597935FF6F; Fri, 13 Feb 2026 13:54:55 +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=1770990896; cv=none; b=OKAzIHFGRy18rkYDMvB6LB3uYDk2oINvJ4Mg9N4DyAolevdNKvIpWf0VNtpxbZeIPAsry7h3pVOLyTCXofenbds1ynKKT7Y3tTQCGstSt5wQzqqVsVnnM7eRMsLVsK5sSoiq5mNDHhhlBr/2yzteJqNOo6i6pJVgGje80Z1eBF0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770990896; c=relaxed/simple; bh=3RwOY9270dEX6YnMAM9EIaOb0J7AXJ2zwi/00dtgR/k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OzDUPB0j0aKZp919/Q+rrctz7ng98aPgaQs58UvduZoqceVx2evDzUiAGH7xF9IJikf/lKzpa7B2EAE1YS6WOVrjgHV/nywlbyAkuUjTNHEWcDKegF88HlK5lhWDTkKGW7IqJkKcZOpIc4aS4hbPbEdn68Pu+v5SXnBqeNd8QXQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pAQywNcn; 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="pAQywNcn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 012EAC116C6; Fri, 13 Feb 2026 13:54:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770990895; bh=3RwOY9270dEX6YnMAM9EIaOb0J7AXJ2zwi/00dtgR/k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pAQywNcnR4/53/onoYsQsOk/p5Oqxxz1vFGvQRTLgZiLnCEOkXRegFIOVI5vWkNuj 9r2+Xvw8SwVXXMLoAjHfb1Zu3Gl2VioxmVrgrmoFPT52OLVpgTZVp43FIhlhigHhxn tR2SVHPTxiSjU4ta5QZOeImb8bsNQv+jvuOiX6K0= 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)" Subject: [PATCH 6.18 43/49] bus: fsl-mc: fix use-after-free in driver_override_show() Date: Fri, 13 Feb 2026 14:48:27 +0100 Message-ID: <20260213134710.441517320@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260213134708.885500854@linuxfoundation.org> References: <20260213134708.885500854@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gui-Dong Han commit 148891e95014b5dc5878acefa57f1940c281c431 upstream. 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: 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 @@ -202,8 +202,12 @@ 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);