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 89F1619D07E for ; Sat, 14 Feb 2026 00:54:30 +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=1771030470; cv=none; b=cirpDZ8d91iNs6rUHksDh3nBZ+h2QKs37iZTBkfizJ8ooW9NohpZ1rjqxukXUhkZExERs1/lAuf7Xe3dSZkg9W54EnB2+1bY/CHQJLUfWA+zOjtSqarTZCrwhNKqDZ+ULoNatjfyRBbWmJaFu7GXzwIQjPK3H7r9iF6XnUvQiFY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771030470; c=relaxed/simple; bh=laCmPknrNJDJ59NiOTvNEWvIYgj2NcZ0tHcEU6jopPs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=p4ZhG0iM7ir/6omHF2ZHoYmv+pI9KHsYtS9Wg8bJUpdRH+xIZWKnhWjT5DvLnonD5RV7C26stncti+cv5V0X0RJ6Jka0P6mOhs5ALcyUEBALjWhGCMv2tY+4UTQ49lhXS+nOIyCqY5VYAOnDNfhtkDyE9ytGF/V+Q/mzRWkf05U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sAcSrBrT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sAcSrBrT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B41EBC16AAE; Sat, 14 Feb 2026 00:54:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771030470; bh=laCmPknrNJDJ59NiOTvNEWvIYgj2NcZ0tHcEU6jopPs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sAcSrBrTJWFHeYPkwIaSwXQw6LuhjBvQOHaPCalE6F+DLI7mmz8+oC9SxjRdJKA3y KmmsOpZ8XrzeUcSwAM5BPpJYkdyuQ5ooYcOs0JOCGmdp6gfXSjx4qg8T8XkKK5+Uc2 jIEvnh1cc3Syfe/8ZCKj92AoNNywFwa7/75SLtiTRJl+QfYQ6o2WLFhGMn7AaMVOEv McG8Ls2AA2WgWUMbAHSq5HR5yaHWOTMyIQ9qzPLHnCI+MA6aVHxIA8h+rrMBrA/t1l S6sdyKjVrAWNUTONT9xVKN9PwhNMsjXXNIJ9ej7TKD4BnbJ8tlh++WkpgiwaxpWmY1 5q7s1jysyo9nQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Gui-Dong Han , Ioana Ciornei , "Christophe Leroy (CS GROUP)" , Sasha Levin Subject: [PATCH 5.15.y 2/2] bus: fsl-mc: fix use-after-free in driver_override_show() Date: Fri, 13 Feb 2026 19:54:27 -0500 Message-ID: <20260214005427.3653008-2-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260214005427.3653008-1-sashal@kernel.org> References: <2026021347-applicant-whooping-9898@gregkh> <20260214005427.3653008-1-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: 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 --- drivers/bus/fsl-mc/fsl-mc-bus.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 8e1000a01231b..dc35de3e4379e 100644 --- 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(struct device *dev, 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); -- 2.51.0